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At least 721 records · Page 40Linked to original sources

PubMed2003

Predictors of successful self control during brain-computer communication.

OBJECTIVES: Direct brain-computer communication uses self regulation of brain potentials to select letters, words, or symbols from a computer menu to re-establish communication in severely paralysed patients. However, not all healthy subjects, or all paralysed patients acquire the skill to self regulate their brain potentials, and predictors of successful learning have not been found yet. Predictors are particularly important, because only successful self regulation will in the end lead to efficient brain-computer communication. This study investigates the question whether initial performance in the self regulation of slow cortical potentials of the brain (SCPs) may be positively correlated to later performance and could thus be used as a predictor. METHODS: Five severely paralysed patients diagnosed with amyotrophic lateral sclerosis were trained to produce SCP amplitudes of negative and positive polarity by means of visual feedback and operant conditioning strategies. Performance was measured as percentage of correct SCP amplitude shifts. To determine the relation between initial and later performance in SCP self regulation, Spearman's rank correlations were calculated between maximum and mean performance at the beginning of training (runs 1-30) and mean performance at two later time points (runs 64-93 and 162-191). RESULTS: Spearman's rank correlations revealed a significant relation between maximum and mean performance in runs 1-30 and mean performance in runs 64-93 (r= 0.9 and 1.0) and maximum and mean performance in runs 1-30 and mean performance in runs 162-191 (r=1.0 and 1.0). CONCLUSIONS: Initial performance in the self regulation of SCP is positively correlated with later performance in severely paralysed patients, and thus represents a useful predictor for efficient brain-computer communication.

Adult↗

PubMed2003

Health problems and psychosocial work environment as predictors of long term sickness absence in employees who visited the occupational physician and/or general practitioner in relation to work: a prospective study.

AIMS: To determine whether psychosocial work environment and indicators of health problems are prospectively related to incident long term sickness absence in employees who visited the occupational physician (OP) and/or general practitioner (GP) in relation to work. METHODS: The baseline measurement (May 1998) of the Maastricht Cohort Study, a prospective cohort study among 45 companies and organisations, was used to select employees at work who indicated having visited the OP and/or GP in relation to work. Self report questionnaires were used to measure indicators of health problems (presence of at least one long term disease, likeliness of having a mental illness, fatigue) and psychosocial work environment (job demands, decision latitude, social support, job satisfaction) as predictors of subsequent sickness absence. Sickness absence data regarding total numbers of sickness absence days were obtained from the companies and occupational health services during an 18 month period (between 1 July 1998 and 31 December 1999). Complete data were available from 1271 employees. RESULTS: After adjustment for demographics and the other predictors, presence of at least one long term disease (OR 2.36; 95% CI 1.29 to 4.29) and lower level of decision latitude (OR 1.69; 95% CI 1.22 to 2.38) were the strongest predictors for sickness absence of at least one month. A higher likelihood of having a mental illness, a higher level of fatigue, a lower level of social support at work, and low job satisfaction were also significant predictors for long term sickness absence, but their effect was less strong. CONCLUSION: In detecting employees at work but at risk for long term sickness absence, OPs and GPs should take into account not only influence of the psychosocial work environment in general and level of decision latitude in particular, but also influence of indicators of health problems, especially in the form of long term diseases.

Adult↗

PubMed2002

Predictors of infection with Trichomonas vaginalis: a prospective study of low income African-American adolescent females.

OBJECTIVES: To identify psychosocial predictors of Trichomonas vaginalis infection among low income African-American adolescent females living in a high risk urban area of the United States. METHODS: Baseline plus 6 and 12 month follow up data collected as part of an HIV prevention intervention trial were utilised. The baseline sample consisted of 522 African-American females, 14-18 years of age. Recruitment sites were located in low income neighbourhoods of Birmingham, Alabama, characterised by high rates of unemployment, substance abuse, violence, teenage pregnancy, and sexually transmitted infections. Self administered vaginal swab specimens were cultured for T vaginalis. Baseline measures collected as part of a self administered survey and face to face interviews were used to predict subsequent infection with T vaginalis at any of the three assessment periods conducted over the span of 1 year. RESULTS: At baseline, 12.9% were diagnosed with T vaginalis. At the 6 and 12 month follow ups, T vaginalis was diagnosed in 8.9% and 10.2%, respectively. The strongest multivariate predictor of T vaginalis infection was biologically confirmed marijuana use; those using marijuana were more than six times as likely to test positive for T vaginalis (adjusted odds ratio (AOR) = 6.2, p = 0.0003). Other multivariate predictors were reporting that typical sex partners were at least 5 years older (AOR = 2.6; p = 0.005), reporting sex with non-steady partners (AOR = 1.9; p = 0.02), and history of delinquency (AOR = 1.3; p = 0.02). The odds of testing positive increased by 31% for every one unit increase on a six item scale measure of delinquency. CONCLUSIONS: Infection with T vaginalis was common and significant multivariate predictors comprised a constellation of problem behaviours, each of which are potentially amenable to behavioural intervention.

Adolescent↗

PubMed2006

Individual-level predictors of cessation behaviours among participants in the International Tobacco Control (ITC) Four Country Survey.

BACKGROUND: The International Tobacco Control (ITC) Four Country Survey (ITC-4) is a prospective cohort study designed to evaluate the psychosocial and behavioural impact of national-level tobacco control policies enacted in the Australia, Canada, the UK, and the USA. Wave 1 of ITC-4 survey was conducted between October 2002 and December 2002. Wave 2 survey was conducted between May 2003 and August 2003. OBJECTIVE: To test for individual-level predictors of smoking cessation behaviours (that is, quit attempts and smoking cessation) among cigarette smokers in the ITC Four Country Study measured between Wave 1 and Wave 2. This set of predictors will serve as the base for evaluating the added effect of tobacco control policies and other factors. METHODS: Respondents included in this study are 6682 adult current smokers in the Wave 1 main survey who completed the Wave 2 follow-up (1665 were in Canada, 1329 were in the USA, 1837 were in the UK and 1851 were in Australia). RESULTS: Factors predictive of making a quit attempt included intention to quit, making a quit attempt in the previous year, longer duration of past quit attempts, less nicotine dependence, more negative attitudes about smoking, and younger age. Lower levels of nicotine dependence were the main factor that predicted future cessation among those that made a quit attempt. CONCLUSION: Intention to quit and other cognitive variables were associated with quit attempts, but not cessation. Behavioural variables related to task difficulty, including measures of dependence, predicted both making attempts and their success. Predictors of making quit attempts and cessation were similar for each of the four countries, but there were some differences in predictors of success.

Adolescent↗

PubMed2003

Endovascular treatment of basilar tip aneurysms with Guglielmi detachable coils: predictors of immediate and long-term results with multivariate analysis 6-year experience.

PURPOSE: To analyze anatomic and clinical results and factors predictive of outcome in treatment of basilar tip aneurysms with Guglielmi detachable coils (GDCs). MATERIALS AND METHODS: During 6 years, 55 unselected consecutive saccular aneurysms in 53 patients (mean age, 47 years) were treated with GDC occlusion. Forty-one (75%) aneurysms were ruptured (Hunt-Hess and Fisher grades were assigned in patients); 14 (25%), unruptured. Clinical and angiographic evaluations were performed 6 months after treatment and during follow-up (mean follow-up, 2 years). Multivariate analysis was used to determine factors predictive of outcome. RESULTS: GDC occlusion was a success in 52 (95%) aneurysms, a failure in two (4%), and not attempted in one (2%). Occlusion at final follow-up, evaluated in 44 aneurysms, was complete in 34 (77%), near complete in four (9%), and incomplete in six (14%). At 6-12 months, mean aneurysmal occlusion rate significantly worsened because of revascularization (P <.001) but improved at final follow-up because of reembolization in 10 aneurysms (P =.009); it remained stable (P =.351) between initial and final follow-up. Multivariate binary logistic regression indicated that before treatment started, aneurysmal neck size was the only independent predictor of initial occlusion rate (P =.002) and revascularization (P =.004). After the initial procedure, sac size and initial occlusion rate were independent predictors of revascularization (P =.004 and.008, respectively), irrespective of neck size. Occlusion rate at 6-12-month follow-up was the only independent predictor of that at final follow-up (P =.021), regardless of shape of aneurysm. Overall morbidity was 2% (one of 51); mortality, 6% (three of 51). Mortality correlated significantly with Hunt-Hess grade 4 at admission (P =.003) and incidence of vasospasm (P =.058). CONCLUSION: GDC occlusion proved to be a safe effective therapeutic alternative to surgery in patients with ruptured or unruptured basilar tip aneurysms. Morphologic and clinical factors were respectively identified as predictors of the optimal anatomic and clinical outcomes.

Adolescent↗

PubMed2003

Screening US for blunt abdominal trauma: objective predictors of false-negative findings and missed injuries.

PURPOSE: To determine the risk for missed injury in patients with blunt abdominal trauma and negative findings at screening ultrasonography (US) and with coexistent hematuria or fracture of the sixth through 12th ribs, lumbar spine, or pelvis. MATERIALS AND METHODS: From a database of 4,000 patients screened with US for blunt abdominal trauma at a level 1 trauma center, the 3,679 patients with negative US findings were retrospectively classified by consensus of two authors into high-risk (n = 494) and low-risk (n = 3,185) groups based on the presence of hypothetical predictors of missed injury: hematuria (n = 96) or fracture of the sixth through 12th ribs (n = 216), lumbar spine (n = 105), or pelvis (n = 174). Outcome in each patient was determined by the same two authors consensually after retrospective review of the trauma registry and all radiologic, surgical, and autopsy reports. The risk for missed abdominal injury was determined for each patient risk group and for each hypothetical predictor. Risks were statistically compared by using the Pearson chi2, Fisher exact, or Fisher-Freeman-Halton exact test, depending on expected frequencies. RESULTS: High-risk patients were 24 times more likely to have abdominal injuries after negative US findings (30 [6.1%] of 494) than were low-risk patients (eight [0.25%] of 3,185) (P <.001). Among high-risk patients, the absolute risks for missed abdominal injury associated with specific predictors were 15.6% (15 of 96 patients) for hematuria, 6.0% (13 of 216) for lower rib fractures, 7.6% (eight of 105) for lumbar spine fractures, and 5.2% (nine of 174) for pelvic fractures. Each of these risks was significantly higher for patients in the high-risk group than for those in the low-risk group (P <.001). CONCLUSION: Hematuria and fracture of the lower ribs, lumbar spine, or pelvis are objective predictors of missed abdominal injury in patients with blunt abdominal trauma and negative US findings, and such patients may benefit from additional screening with computed tomography.

Abdominal Injuries↗

PubMedDate not supplied

Predictors of onset of wheezing in grain elevator workers.

A longitudinal study of Canadian grain elevator workers over a 12-year period was conducted. Data on respiratory symptoms and pulmonary function tests were collected once every three years as part of the Grain Dust Medical Surveillance Program started by Labour Canada in 1978; each three-year interval was called a 'cycle'. Of workers who had two or more observations, 1848 subjects (67.2%) were free of respiratory symptoms (wheeze, dyspnea, cough or sputum) at the baseline (cycle II). Predictors of first episode of wheezing were examined in these symptoms-free grain workers. Baseline mean age +/- SD of the grain workers was 34.0 +/- 11.4 years and mean duration of work in the industry was 9.9 +/- 8.7 years. Of the 1848 symptoms-free grain workers at cycle II, 203 (11.0%) subsequently reported wheezing during the study. Cox's proportional hazards model for analysis of survival data was used to determine significant predictors of first episode of wheezing. Significant predictors for first episode of wheezing were current smoking (relative risk [RR] 2.33; 95% CI 1.63 to 3.33; P<0.0001) and baseline forced expiratory volume in 1 s to forced vital capacity ratio [RR 0.02; 95% CI 0.003 to 0.20; P<0.0001). Baseline pulmonary function measurements and smoking habits appear to be important predictors of future development of asthma-like symptoms in grain elevator workers.

Adult↗

PubMedDate not supplied

Predictors of longitudinal changes in pulmonary function among swine confinement workers.

OBJECTIVE: To determine predictors of longitudinal changes in pulmonary function in swine confinement workers. DESIGN: Longitudinal study conducted from November 1989 to June 1991 and January 1994 to May 1995. SETTING: Swine confinement workers in Saskatchewan. PARTICIPANTS: Forty-two swine confinement workers who were studied in 1989/90 and studied again in 1994/95. RESULTS: Of 98 male swine confinement workers (mean age SD 36.3 11.1 years) studied at baseline, 42 were studied again five years following. Complete information on baseline across-shift pulmonary function (preshift forced expiratory volume in 1 s [FEV1], forced vital capacity [FVC], and every 2 h FEV1 and FVC during the shift), and five-year follow-up pulmonary function (with FEV1 and FVC) were available on all 42 subjects. Mean across-shift changes (preshift measurement to last measurement of the day) at baseline were -159. 8 61.7 mL in FEV1 and -35.3 65.6 mL in FVC. Mean annual rate change between baseline and follow-up for FEV1 was -53.9 61.7 mL/year and for FVC -48.9 71.6 mL/year. After adjusting for age, height, smoking and hours spent in the barn, the baseline across-shift change in FEV1 and FVC was a significant predictor of annual rate change in FEV1 (P=0.01) and FVC (P=0.02), respectively. To determine the effects of indoor air quality on longitudinal lung function decline, indoor air environmental measurements were analysed. Complete information on respiratory health and indoor air quality was available on 34 of the 42 subjects. Assessment of indoor environment of swine barns included a summer and winter measurement for airborne dust, gases and endotoxin levels. After adjusting for age, height, smoking, ammonia and hours spent in the barn, the endotoxin level (Eu/mg)was a significant predictor of annual rate change for FEV1 but not FVC. CONCLUSIONS: These results suggest that shift change is an important predictor of longitudinal changes in lung function in swine confinement workers and that endotoxin exposures may mediate annual decline in FEV1 in these workers.

Adolescent↗

PubMed2005

Predictors of the response to gefitinib in refractory non-small cell lung cancer.

Gefitinib, an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, has a response rate of 10% to 20% in refractory non-small cell lung carcinoma. Although female gender, adenocarcinoma, and never having smoked are possible markers of a favorable response, mutations of the EGFR gene have also been reported to be highly significant predictors of response. Seventy patients with relapsed non-small cell lung carcinoma were enrolled in the Expanded Access Program. After the drug became available commercially, 28 more patients were treated with gefitinib. Response evaluations were feasible in 80 patients. Twenty-seven tumor specimens (8 responders and 19 nonresponders) were available for the sequence analysis of the EGFR gene. The response rate was 25% (20/80) and the disease control rate (remission + stable disease) was 47.5% (38/80). The response rate was significantly higher for adenocarcinoma (41.0%) versus non-adenocarcinoma (9.8%, P = 0.001), in those who never smoked (58.8%) versus smokers (15.9%, P < 0.001), and in females (42.1%) versus males (19.7%, P = 0.049). A deletion or mutation of the EGFR gene was found in six of eight responders. Remission was noted in all patients with a mutation, whereas the response rate was 9.5% (2/21) in patients without a mutation (P < 0.001). The predictors of response showed significant correlations with survival and time to progression. In a multivariate logistic analysis, the independent predictors of response were smoking history and adenocarcinoma. Given that 9.5% of smokers and 6.7% of those with non-adenocarcinoma showed a mutation of the EGFR gene, the genetic profile may replace those variables as an independent predictor of a response.

Adenocarcinoma↗

PubMed1998

Predictors of death and other cardiac events within 2 years after coronary artery bypass grafting.

RESULTS: In 1,841 patients who underwent coronary artery bypass grafting (CABG) we evaluated risk indicators for death and other cardiac events during 2 years of follow-up. Independent predictors of death were: a history of congestive heart failure, diabetes mellitus and renal dysfunction prior to CABG. Independent predictors of death, acute myocardial infarction (AMI), CABG or percutaneous transluminal coronary angioplasty (PTCA) were: a small body surface area, a history of congestive heart failure, diabetes mellitus and smoking prior to CABG. Independent predictors of death, AMI, CABG, PTCA or rehospitalization for a cardiac reason were: angina functional class, previous AMI, a history of congestive heart failure and renal dysfunction prior to CABG. CONCLUSION: When using various definitions of a cardiac event after CABG, various risk indicators for death or such an event can be found. Our data suggest that anamnestic information prior to CABG indicating a depressed myocardial function or severe myocardial ischemia are more important predictors of outcome than the information gained from cardioangiography.

Angina Pectoris↗

PubMed1998

Predictors of outcome in patients with implantable cardioverter defibrillators.

UNLABELLED: This study determined the impact of clinical characteristics on shock occurrence and survival in patients with implantable cardioverter-defibrillator (ICD). METHODS AND RESULTS: During a follow-up of 27 +/- 18 months, the actuarial incidence of appropriate shocks in 200 consecutive patients was 18, 36 and 72% at 1, 3, and 5 years, respectively. Coronary artery disease was the only significant predictor for shock occurrence (relative risk 1.32, p = 0.03). The actuarial incidence of total mortality was 10, 17 and 33% at 1, 3, and 5 years, respectively. The most powerful predictors for total mortality were: New York Heart Association functional class (NYHA) III (relative risk 4.8, p = 0.001) and a history of congestive cardiac failure (relative risk 3.6, p = 0.01). CONCLUSION: During long-term follow-up, the majority of patients receive appropriate shocks. No strong predictors for shock occurrence can be identified from the data analyzed. A history of congestive cardiac failure and the NYHA III are the most powerful predictors for total mortality. These clinical factors may provide valuable criteria to identify patients who will benefit from the implantation of ICD.

Arrhythmias, Cardiac↗

PubMed2003

Cause is the main predictor of outcome in patients with pontine hemorrhage.

BACKGROUND: Pontine hemorrhages frequently lead to death or severe disability. Predictors of early mortality have been previously described but little is known about the factors influencing long-term disability. OBJECTIVE: Determine clinical predictors of long-term outcome in a large hospital series of patients with acute pontine hemorrhage. METHODS: Review of all patients with acute pontine hemorrhage admitted to a single tertiary center from 1990 to 2002 who underwent a diagnostic workup including brain magnetic resonance imaging (MRI). Long-term outcome was rated using the modified Rankin Scale (mRS) score at the time of the last follow-up. Odds ratios (ORs) for predictive factors were calculated using univariate and multivariable logistic regression analysis. Level of significance was established at p < 0.01. RESULTS: We identified 44 consecutive patients with acute pontine hemorrhage. Twenty-four patients had primary hemorrhages (no cause other than hypertension). Arteriovenous or cavernous malformations were documented by brain MRI in 20 patients. Patients with primary hemorrhages had worse Glasgow Coma Scale sum scores (p = 0.01) and more unfavorable CT patterns (p = 0.005) at presentation. Eighteen percent of the patients died in the hospital. Mean follow-up among survivors was 20 months (range 3-144 months). Twenty-two percent of the patients remained severely disabled (mRS greater than 2) at 3 months and at the time of the last follow-up. All deaths occurred in patients with primary pontine hemorrhage. Poor outcome (death or severe disability) was more frequent in patients with primary hemorrhages when compared with patients harboring cavernous malformations (62 versus 5%; p < 0.01). Primary hemorrhage was the only independent predictor of poor outcome in multivariable regression analysis (OR 12; p = 0.029). CONCLUSIONS: Cause is a main predictor of clinical and radiological severity at presentation and outcome in patients with pontine hemorrhage. The first episode of hemorrhage in patients with brainstem cavernous malformations is usually benign. Pontine hemorrhage associated with prior hypertension is much more devastating.

Adolescent↗

PubMed2000

Paraoxonase (PON1) phenotype is a better predictor of vascular disease than is PON1(192) or PON1(55) genotype.

The paraoxonase (PON1) PON1-Q192R and PON1-L55M polymorphisms have been inconsistently associated with vascular disease. Plasma PON1 activity phenotypes vary markedly within genotypes and were, therefore, expected to add to the informativeness of genotype for predicting vascular disease. The case-control sample included 212 age- and race-matched men (mean age 66.4 years). The 106 carotid artery disease (CAAD) cases had >80% carotid stenosis, and the 106 controls had <15%. Two PON1 substrate hydrolysis rates (paraoxon [POase] and diazoxon [DZOase]) were significantly lower in cases than in controls and were significant predictors of CAAD by use of logistic regression (POase, P=0.005; DZOase, P=0.019). DZOase predicted vascular disease independently of lipoprotein profile, high density lipoprotein subfractions, apolipoprotein A-I, and smoking. PON1-192 and PON1-55 genotypes or haplotypes did not predict case-control status unless the activity phenotype was also included as a predictor by use of logistic regression. When phenotype was included as a predictor, PON1-192 and PON1-55 genotypes or combined haplotypes were significant predictors (P<0.05). In conclusion, examining PON1-192 and/or PON1-55 genotypes alone may mistakenly lead to the conclusion that there is no role of PON1 in CAAD. These results support the benefit of a "level crossing" approach that includes intervening phenotypes in the study of complexly inherited disease.

Aged↗

PubMed2004

Incidence, mechanism, predictors, and long-term prognosis of late stent malapposition after bare-metal stent implantation.

BACKGROUND: Predictors and long-term prognosis of late stent malapposition (LSM) after bare-metal stent (BMS) implantation are unknown. METHODS AND RESULTS: We evaluated the incidence, mechanisms, predictors, and long-term prognosis of LSM after BMS implantation in 881 patients (992 native lesions) in whom intravascular ultrasound was performed at index and 6-month follow-up. LSM was defined as a separation of stent struts from the intimal surface of the arterial wall that was not presented at stent implantation. LSM occurred in 54 patients with 54 lesions (5.4% overall); the incidence was 10.3% (9 of 87) after directional coronary atherectomy (DCA) before stenting and 11.5% (11 of 96) after primary stenting in acute myocardial infarction (P=0.031 and P=0.007, respectively, versus elective stenting with conventional balloon pre-dilation, 4.3% [30 of 692]). There was an increase of external elastic membrane area (18.9+/-3.9 to 24.5+/-5.1 mm2, P<0.001) that was greater than the increase in plaque area (9.6+/-3.0 to 11.4+/-2.9 mm2, P<0.001). Independent predictors of LSM were primary stenting in acute myocardial infarction (P=0.023, OR=2.55, 95% CI=1.14 to 5.69) and DCA before stenting (P=0.025, OR=3.02, 95% CI=1.15 to 7.96). There were no significant differences in major adverse cardiac events between LSM and non-LSM groups during mean 3-year follow-up (1.9% versus 1.8%, respectively, P=NS). CONCLUSIONS: LSM occurs in approximately 5% after BMS implantation. The predictors of LSM are primary stenting in acute myocardial infarction and DCA before stenting. Compared with complete stent apposition at follow-up, LSM after BMS implantation is not associated with any major adverse cardiac events during a mean 3-year follow-up after detection of LSM.

Aged↗

PubMed2004

Prevalent low-frequency oscillation of heart rate: novel predictor of mortality after myocardial infarction.

BACKGROUND: This study evaluates a novel method for postinfarction risk stratification based on frequency-domain characteristics of heart rate variability (HRV) in 24-hour Holter recordings. METHODS AND RESULTS: A new risk predictor, prevalent low-frequency oscillation (PLF), was determined in the placebo population of the European Myocardial Infarction Amiodarone Trial (EMIAT). Frequencies of peaks detected in 5-minute low-frequency HRV spectra were averaged to obtain the PLF index. PLF >or=0.1 Hz was the strongest univariate predictor of all-cause mortality associated with relative risk of 6.4 (95% CI, 3.9 to 10.6; P<10(-12)). In a multivariate Cox's regression model including clinical risk factors, mean RR interval, HRV index, low- and high-frequency HRV spectral power, and heart rate turbulence, PLF was the most powerful mortality predictor, with a relative risk of 4.6 (95% CI, 2.2 to 9.3; P=0.00003). Predictive power of PLF was blindly validated in the population of the Autonomic Tone and Reflexes After Myocardial Infarction (ATRAMI) trial. PLF >or=0.1 Hz was associated with univariate relative risk of 6.1 (95% CI, 2.9 to 12.9; P<10(-5)) for cardiac mortality or resuscitated cardiac arrest. In multivariate Cox's regression model including age, left ventricular ejection fraction, baroreflex sensitivity, mean RR interval, standard deviation of normal RR intervals, low- and high-frequency HRV spectral power, and heart rate turbulence, only left ventricular ejection fraction and PLF were significant predictors, with relative risks of 4.2 (95% CI, 1.5 to 11.7; P=0.007) and 3.6 (95% CI, 1.3 to 10.5; P=0.02), respectively. CONCLUSIONS: An innovative analysis of frequency-domain HRV, which characterizes the distribution of spectral power within the low-frequency band, is a potent and independent risk stratifier in postinfarction patients.

Adrenergic beta-Antagonists↗

PubMed1999

Predictors of proximal aortic dissection at the time of aortic valve replacement.

BACKGROUND: Type I aortic dissection develops in 0.6% of patients late after aortic valve replacement (AVR), and 13% of patients with type I aortic dissections have a history of AVR. Predictors of aortic dissection at AVR, however, have not been characterized. METHODS AND RESULTS: A study group of 33 patients with type I aortic dissection had aortic surgery 49+/-55 months after routine AVR. A group of 101 controls, who did not have morphological progression of aortic diameters >/=6 years after AVR, was used to identify predictors of postsurgical dissection. Multivariate analysis identified aortic regurgitation (P<0.002) and fragility (P<0.001) or thinning of the aortic wall (P<0.007) at AVR as predictors, associated with a 14%, 22%, and 7% probability of late aortic dissection, respectively. Clamping times, types of valve prostheses, concomitant coronary artery bypass grafting, and mean ascending aortic diameters of 43+/-10 mm at AVR did not predict late dissection. A separate analysis of 29 nondissecting aneurysms of the ascending aorta developing 104+/-64 months after routine AVR revealed younger age at AVR (P<0.003) and congenitally bicuspid aortic valves (P<0.03) as predictors of late aneurysm formation. CONCLUSIONS: Aortic regurgitation combined with fragile and thinned aortic walls in patients with moderate aortic dilation may reflect aortic root disease, with a high risk for postsurgical aortic sequelae if it is treated incompletely by isolated valve replacement.

Adult↗

PubMed1983

Predictors of systolic blood pressure response to treadmill exercise: the Lipid Research Clinics Program Prevalence Study.

We used multiple linear regression to study predictors of systolic blood pressure response (SBPR), i.e., the increase in pressure above baseline after 3, 6, and 9 min of treadmill exercise, in 4262 men and women. Predictors considered were usual SBP, the difference (delta SBP) between resting SBP and SBP immediately before exercise, age, education, obesity index, alcohol consumption, cigarette smoking, preexercise heart rate and, in women, gonadal hormone use. In men, age, obesity index, and cigarette smoking were positively associated with SBPR and in women 20 to 49 years old, age, obesity index, and alcohol consumption were positively associated with SBPR. In women 50 years old or older, usual SBP was negatively associated with SBPR. In both men and women a larger delta SBP was associated with a smaller SBPR. These results help explain the considerable variation in SBPR, and the delta SBP results suggest that potential SBPR may, to certain extent, have a specific, finite range. The similarity of predictor variables for SBPR to predictor variables for hypertension is concordant with the previous observation that a high SBPR may foreshadow subsequent hypertension.

Adult↗

PubMed1993

Progressive left ventricular dysfunction and remodeling after myocardial infarction. Potential mechanisms and early predictors.

BACKGROUND: Left ventricular enlargement and the development of chronic heart failure are potent predictors of survival in patients after myocardial infarction. Prospective studies relating progressive ventricular enlargement in individual patients to global and regional cardiac dysfunction and the onset of late chronic heart failure are not available. It was the aim of this study to define the relation between left ventricular dilatation and global and regional cardiac dysfunction and to identify early predictors of enlargement and chronic heart failure in patients after myocardial infarction. METHODS AND RESULTS: Left ventricular volumes, regional area shrinkage fraction in 18 predefined sectors (gated single photon emission computed tomography), global ejection fraction, and hemodynamics at rest and during exercise (supine bicycle, 50 W, 4 minutes, Swan-Ganz catheter) were assessed prospectively 4 days, 4 weeks, 6 months, and 1.5 and 3 years after first myocardial infarction. Seventy patients were assigned to groups with progressive, limited, or no dilatation. Patients without dilatation (n = 38) maintained normal volumes and hemodynamics until 3 years. With limited dilatation (n = 18), left ventricular volume increased up to 4 weeks after infarction and stabilized thereafter; depressed stroke volume was restored 4 weeks after infarction and then remained stable at rest. Wedge pressure during exercise, however, progressively increased. With progressive dilatation (n = 14), depressed cardiac and stroke indexes were also restored by 4 weeks but progressively deteriorated thereafter. Area shrinkage fraction as an estimate of regional left ventricular function in normokinetic sectors at 4 days gradually deteriorated during 3 years, but hypokinetic and dyskinetic sectors remained unchanged. Global ejection fraction fell after 1.5 years, whereas right atrial pressure, wedge pressure, and systemic vascular resistance increased. By multivariate analysis, ejection fraction and stroke index at 4 days, ventriculographic infarct size, infarct location, and Thrombolysis in Myocardial Infarction trial grade of infarct artery perfusion were significant predictors of progressive ventricular enlargement and chronic dysfunction. CONCLUSIONS: Almost 26% of patients may develop limited left ventricular dilatation within 4 weeks after first infarction, which helps to restore cardiac index and stroke index at rest and to preserve exercise performance and therefore remains compensatory. A somewhat smaller group (20%) develops progressive structural left ventricular dilatation, which is compensatory at first, then progresses to noncompensatory dilatation, and finally results in severe global left ventricular dysfunction. In these patients, depression of global ejection fraction probably results from impairment of function of initially normally contracting myocardium. Early predictors from multivariate analysis allow identification of patients at high risk for progressive left ventricular dilatation and chronic ventricular dysfunction within 4 weeks after acute infarction.

Aged↗