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Biomedical subjects

Colleen Gorman Koch

Publications and source records attributed to Colleen Gorman Koch.

16 recordsLinked to original sources
PubMed2006

Increased risk associated with combined carotid endarterectomy and coronary artery bypass graft surgery: a propensity-matched comparison with isolated coronary artery bypass graft surgery.

OBJECTIVE: Risk associated with combined carotid endarterectomy and coronary artery bypass graft surgery (CEA/CABG) is controversial. The present study objective was to compare morbidity and mortality outcomes in well-matched patients who underwent combined CEA/CABG surgery with patients undergoing isolated CABG surgery with and without a history of a prior CEA. DESIGN: This investigation was designed as a retrospective case-controlled study using data from the Cardiothoracic Anesthesia Patient Registry in a single tertiary institution. The patient population consisted of 1,698 isolated CABG surgery patients with carotid artery stenosis >40%, 708 patients who underwent an isolated CABG surgery but had a history of a prior CEA, and 272 combined CEA/CABG surgery patients who underwent surgery from January 4, 1993, through June 30, 2003. Propensity modeling techniques were used to calculate a propensity score for each patient. Greedy matching resulted in 272 propensity-matched pairs of combined CEA/CABG and isolated CABG patients (primary analysis) and 241 propensity-matched pairs of combined CEA/CABG surgery and isolated CABG surgery with previous CEA patients (secondary analysis). A Fisher exact, chi-square, Wilcoxon rank sum, and Student t test were applied appropriately to compare the propensity-matched pairs. RESULTS: The distribution of covariates among the propensity-matched combined CEA/CABG and isolated CABG groups were similar. Among the propensity-matched pairs in the primary analysis, overall morbidity and mortality were higher in the combined CEA/CABG group compared with the CABG group alone (overall morbidity 15% v 8.8%, p = 0.025, and mortality 5.2% v 1.1%, p = 0.007, respectively). Median intensive care unit (ICU) length of stay was longer (47 v 31 hours, p = 0.004) and hospital length of stay was longer (12 v 9 days, p < 0.001) for the combined CEA/CABG surgery compared with isolated CABG surgery, respectively. Postoperative cardiac, neurologic, serious infection, and renal morbid events were similar between the 2 groups. In the secondary analysis, the rates of mortality, overall morbidity, and neurologic morbidity were similar between the groups, whereas the median ICU and hospital length of stay were significantly longer in the combined CEA/CABG group (47.6 v 39.8 hours, p = 0.025, and 12.0 v 9.0 days, p < 0.001, respectively). CONCLUSIONS: Increased mortality and overall morbidity outcomes were found in the combined CEA/CABG group when compared with well-matched isolated CABG patients, but similar when compared with well-matched isolated CABG patients with a history of previous CEA. Patients undergoing combined CEA/CABG procedures had significantly longer ICU and hospital lengths of stay compared with patients undergoing isolated CABG procedures.

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PubMed2006

Persistent effect of red cell transfusion on health-related quality of life after cardiac surgery.

BACKGROUND: Although red blood cell transfusion has been associated with an increase in early morbid outcomes and reduced long-term survival after cardiac surgery, its relationship to functional quality of life after surgery has not been previously explored. Our objective was to investigate the relationship between perioperative red blood cell and component transfusion and functional health-related quality of life 6 to 12 months after cardiac surgery. METHODS: Of 12,536 patients undergoing cardiac surgical procedures between May 1995 and January 1999, 7,321 completed a self-administered Duke Activity Status Index (DASI) survey preoperatively and least one follow-up survey at nominally 6 or 12 months postoperatively. The influence of baseline DASI, preoperative risk factors, clinical status, laboratory values, operative events, and postoperative morbidities on follow-up DASI were examined with ordinal regression modeling. RESULTS: After adjustment for preoperative DASI, demographic, cardiac and noncardiac comorbidity, type of surgery, postoperative complications, and interval between follow-up DASI, during which patients continued to improve (p < 0.0001), postoperative functional status after cardiac surgery was incrementally worse the more perioperative red cells (p < 0.0001) and platelets (p = 0.02) that had been transfused. CONCLUSIONS: Red blood cell and platelet transfusion have an unintended persistently negative risk-adjusted effect on health-related quality of life after cardiac surgery that extends well beyond initial hospitalization. Reductions in functional recovery paralleled increasing units of red blood cells transfused.

Activities of Daily Living↗
PubMed2006

Transfusion in coronary artery bypass grafting is associated with reduced long-term survival.

BACKGROUND: Perioperative red blood cell (PRBC) transfusion has been associated with early risk for morbid outcomes, but risk related to long-term survival has not been thoroughly explored. Therefore, we examined the influence of PRBC transfusion and component therapy on long-term survival after isolated coronary artery bypass grafting after controlling for the effect of demographics, comorbidities, operative factors, and the early hazard for death. METHODS: The US Social Security Death Index was used to ascertain survival status for 10,289 patients who underwent isolated coronary artery bypass grafting from January 1, 1995 through June 28, 2002. The outcome measure was all-cause mortality during the follow-up period. Unadjusted survival estimates were performed using the Kaplan-Meier techniques. Survival curves for transfusion status were compared with the log-rank test. The parametric decomposition model was used for risk-adjusted survival. A balancing score was calculated for each patient and forced into the final model. RESULTS: Survival among transfused patients was significantly reduced as compared with nontransfused patients. The instantaneous risk of death displayed a biphasic pattern: a declining hazard phase from the time of the operation (early hazard) up until 6 months postoperatively and then a late hazard that continued out until about 10 years. Transfusion of red cells was associated with a risk-adjusted reduction in survival for both the early (0.34 +/- 0.02, p < 0.0001) and late phases (0.074 +/- 0.016, p < 0.0001). CONCLUSIONS: Perioperative PRBC transfusion is associated with adverse long-term sequela in isolated CABG. Attention should be directed toward blood conservation methods and a more judicious use of PRBC.

Age Factors↗
PubMed2006

Red cell transfusion is associated with an increased risk for postoperative atrial fibrillation.

BACKGROUND: Atrial fibrillation (AF) is a common complication after cardiac surgery and is associated with increased resource utilization. Recent evidence supports a role of inflammation in the development of AF. It is also known that red blood cell transfusion modulates inflammation by increasing plasma levels of inflammatory markers. Therefore, we tested the hypothesis that red blood cell transfusion increases the risk of postoperative AF for patients undergoing cardiac surgery. METHODS: Between February 2002 and January 2005, 5,841 patients underwent isolated coronary artery bypass grafting with or without valve replacement. Patient and procedural variables associated with development of new-onset AF were identified by logistic regression. Propensity score matching was used to confirm results. RESULTS: In addition to older age, prior history of AF, higher preoperative hematocrit, beta-blocker withdrawal, longer aortic clamp time, valve surgery, and intensive care unit inotropic usage, intensive care unit red blood cell transfusion increased risk for AF (odds ratio per unit transfused, 1.18; 95% confidence limits, 1.14, 1.23; p < 0.0001). For the 1,360 propensity-matched pairs, intensive care unit red blood cell transfusion was associated with a significant increase in new-onset AF (620 [46%] versus 522 [38%]; p < 0.001). CONCLUSIONS: Intensive care unit red blood cell transfusion is associated with increased occurrence of postoperative AF after cardiac surgery. This factor should be considered in identifying patients who might benefit from prophylaxis to prevent this common postoperative complication.

Aged↗
PubMed2006

Morbidity and mortality risk associated with red blood cell and blood-component transfusion in isolated coronary artery bypass grafting.

OBJECTIVE: Our objective was to quantify incremental risk associated with transfusion of packed red blood cells and other blood components on morbidity after coronary artery bypass grafting. DESIGN: The study design was an observational cohort study. SETTING: This investigation took place at a large tertiary care referral center. PATIENTS: A total of 11,963 patients who underwent isolated coronary artery bypass from January 1, 1995, through July 1, 2002. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Among the 11,963 patients who underwent isolated coronary artery bypass grafting, 5,814 (48.6%) were transfused. Risk-adjusted probability of developing in-hospital mortality and morbidity as a function of red blood cell and blood-component transfusion was modeled using logistic regression. Transfusion of red blood cells was associated with a risk-adjusted increased risk for every postoperative morbid event: mortality (odds ratio [OR], 1.77; 95% confidence interval [CI], 1.67-1.87; p<.0001), renal failure (OR, 2.06; 95% CI, 1.87-2.27; p<.0001), prolonged ventilatory support (OR, 1.79; 95% CI, 1.72-1.86; p<.0001), serious infection (OR, 1.76; 95% CI, 1.68-1.84; p<.0001), cardiac complications (OR, 1.55; 95% CI, 1.47-1.63; p<.0001), and neurologic events (OR, 1.37; 95% CI, 1.30-1.44; p<.0001). CONCLUSIONS: Perioperative red blood cell transfusion is the single factor most reliably associated with increased risk of postoperative morbid events after isolated coronary artery bypass grafting. Each unit of red cells transfused is associated with incrementally increased risk for adverse outcome.

Aged↗
PubMed2005

Impact of prosthesis-patient size on functional recovery after aortic valve replacement.

BACKGROUND: Prosthesis-patient size mismatch results when an implanted prosthetic aortic valve is of insufficient size for a patient's body surface area. The relation between prosthesis-patient size and functional capacity and adverse postoperative outcome is inconsistent. Our objectives were to examine the impact of valve replacement, continuous prosthesis-patient size, and other factors on functional recovery after aortic valve replacement (AVR) with the Duke Activity Status Index (DASI). METHODS AND RESULTS: From June 15, 1995, through May 14, 1998, 1108 patients underwent AVR after completing a DASI survey. Of these, 1014 completed a postoperative DASI survey at an average of 8.3 months postoperatively. Logistic ordinal regression was used to examine the influence of demographic variables, comorbidities, baseline DASI scores, indexed valve orifice area, standardized orifice size, and postoperative morbid events on postoperative DASI. There was overall improvement in postoperative functional recovery reflected by median preoperative and postoperative DASI scores of 29 and 46, P<0.001, respectively. Neither indexed orifice area, P=0.94, nor standardized orifice size, P=0.96, was associated with functional recovery. Female sex, increasing age, elevated serum creatinine, increased central venous pressure, and red blood cell transfusion were factors associated with poor postoperative functional recovery. CONCLUSIONS: A majority of patients report improvement in functional quality of life early after AVR. Similar functional recovery was demonstrated for patients along the full spectrum of valve sizes indexed to body size, even for values considered to represent severe mismatch for patient size. Factors other than prosthesis-patient size influence functional quality of life early after AVR.

Adult↗
PubMed2005

"Renal dose" dopamine is associated with the risk of new-onset atrial fibrillation after cardiac surgery.

OBJECTIVE: "Renal dose" dopamine (rDA; 1-3 microg/kg per min) is administered to patients after cardiac surgery to preserve or improve renal function. Many of these patients develop new-onset postoperative atrial fibrillation or atrial flutter (pAF) that could be related to rDA administration. The objective of this investigation was to determine whether there was an association between rDA and new-onset pAF in patients undergoing coronary artery bypass grafting with cardiopulmonary bypass (CABG). SETTING: Research hospital. SUBJECTS: The study population consisted of 1,731 patients undergoing CABG. INTERVENTIONS: CABG with and without rDA. DESIGN: After approval by the institutional review board, a retrospective study using the Cardiothoracic Anesthesia Patient Registry was undertaken to determine the association between rDA and pAF in patients undergoing CABG. Patients with a documented history of atrial fibrillation, those who required inotrope use during or after surgery, and those having valve surgery were excluded. MEASUREMENTS AND MAIN RESULTS: One-thousand seven-hundred thirty-one patients undergoing CABG during the period of January 1, 2000, through June 30, 2002, were the study population; of these, 15.0% (260/1,731) developed pAF. The incidence of pAF was 23.3 % (41/176) among patients who received rDA and 14.1% (219/1,555) among those who did not receive rDA. In the multivariable logistic regression model, patient age, gender, chronic obstructive pulmonary disease or asthma, and rDA were associated with pAF (p < .01). Receipt of rDA increased the odds of developing pAF by 74%, independent of the effect of other variables. CONCLUSIONS: Renal-dose dopamine is associated with a 1.74 odds ratio of pAF developing after CABG.

Atrial Fibrillation↗
PubMed2004

Health-related quality of life after coronary artery bypass grafting: a gender analysis using the Duke Activity Status Index.

OBJECTIVE: Our objectives were to document the preoperative and postoperative functional status of patients undergoing coronary artery bypass grafting, to examine factors that influence functional recovery, and to determine whether gender differences exist in the preoperative and postoperative functional status with the Duke Activity Status Index. METHODS: One thousand eight hundred twenty-five patients undergoing isolated coronary artery bypass grafting had baseline and follow-up quality-of-life surveys. Mean follow-up from baseline to postoperative Duke Activity Status Index was 8.0 months for women and men. The influence of 47 variables, in addition to baseline scores on postoperative functional status, was examined with logistic ordinal modeling. An ordinal model for the follow-up score was determined by means of backward selection, with variables retained if they satisfied the criterion of a P value of less than.05. RESULTS: Median baseline Duke Activity Status Index scores (women, 21.5; men, 32.2; P <.001) and first follow-up scores (women, 42.7; men, 58.2; P <.001) were lower in women than in men. Patients who were older and those who had chronic obstructive pulmonary disease, myocardial infarction, stroke, diabetes, vascular disease, postoperative serious infection, and return to the operating room had lower postoperative scores. After adjusting for these factors, women still had lower follow-up scores (odds ratio for men, 2.1 [95% confidence interval, 1.7-2.6]; P <.001). CONCLUSIONS: A number of preoperative factors, operative variables, and postoperative events are associated with functional recovery after coronary revascularization. In addition, female gender is associated with more postoperative functional impairment after adjusting for these perioperative variables.

Adult↗
PubMed2003

Gender and outcomes after coronary artery bypass grafting: a propensity-matched comparison.

OBJECTIVE: Our objective is to determine whether gender is a marker or a causal influence for poor outcomes after coronary revascularization. METHODS: Propensity-modeling techniques were used to investigate whether gender adversely impacts outcomes after coronary revascularization. A parsimonious explanatory model was developed by bootstrap bagging with variable selection from 64 baseline and 37 operative variables. Propensity scores were calculated from a logistic model that included the parsimonious model and additional baseline variables. Greedy matching techniques were applied to match female and male patients to the nearest propensity scores. Comparisons were made among the propensity-matched women and men. RESULTS: Of the 15,597 patients undergoing isolated coronary artery bypass graft surgery, only 26% of the 3596 women were matched on propensity scores with men. Distribution of covariates among the matched pairs was, on average, equal. Postoperative mortality (P =.76), neurologic morbidity (global deficit P =.07, focal deficit P =.51), infection (sepsis P =.88), mediastinitis (P =.18), renal failure (P =.84), intra-aortic balloon pump usage (P =.61), and reoperation for bleeding (P =.10) were similar among women and men. Occurrence of Q-wave myocardial infarction (P = <.01), postoperative inotropic usage (P = <.01), and prolonged ventilatory support (P =.02) were more common in women compared with propensity-matched men. CONCLUSIONS: The preoperative profiles of women and men are markedly different. Propensity matching women and men was difficult, because only 26% of women were able to be matched with men. However, in well-matched patients, female gender was not associated with increased mortality and had minimal impact on morbidity after coronary artery bypass grafting.

Aged↗
PubMed2003

Gender profiling in coronary artery bypass grafting.

OBJECTIVE: Although women are reported to be at increased risk of poor outcome after coronary artery bypass grafting, female gender may simply be a marker of a high-risk profile. Therefore, the objective of this study was to characterize the difference between the female and male profiles of patients presenting for coronary artery bypass grafting. METHODS: From January 1993 to June 2002, 15,597 patients underwent isolated coronary artery bypass grafting at a single institution. Multivariable logistic regression was used to develop a model of female gender. RESULTS: Of 15,597 patients, 3596 (23%) were women. Eighteen variables were predictive of the female gender profile, including shorter stature, increased weight, more hypertension, insulin-treated diabetes mellitus, heart failure, and higher triglyceride and high-density lipoprotein cholesterol levels. Hematocrit, bilirubin, and creatinine values were lower in women compared with men. CONCLUSIONS: The preoperative profiles of women and men undergoing coronary artery bypass grafting are dissimilar. Statistical modeling techniques provide a unique perspective on the preoperative profile of the female patient, who is known to be at a higher risk undergoing coronary artery bypass grafting.

Anthropometry↗
PubMed2003

What does transesophageal echocardiography add to valvular heart surgery?

No single monitoring tool in the last decade has had more of an effect on intraoperative decision making and surgical management of cardiac valvular pathologies than has TEE. It has become the standard of care for evaluating reparative valvular procedures, thus providing an immediate gauge of the surgical results and helping to avoid suboptimal surgical outcomes. As the technology of TEE and its application advance, so too should the ability to diagnose and manage valvular pathologies, broaden the range of surgical options, and ultimately improve patient outcomes.

Aortic Valve↗
PubMed2003

Gender and cardiac surgery.

The increased operative mortality and morbidity of women compared with men undergoing CABG surgery results from multiple differences in presentation, preoperative risk profile, and surgical factors. Investigators have found consistently that women present with a different preoperative risk profile than do men. Women more commonly have factors associated with increased short- and long-term mortality, such as less frequent use of IMA grafts. Differences in study design and patient population may contribute to variability in short- and long-term mortality among the various studies. The lack of representation of women in older clinical trials has hindered our understanding of the management of CAD in women; this situation must be remedied in future studies, [95]. Known physiologic and anatomic differences must be evaluated for their effects on outcomes. Further studies are needed to evaluate gender-related differences in autonomic responses to acute coronary occlusion, complications related to cardiopulmonary bypass, susceptibility to abnormalities in coagulation, and other factors that might account for discrepant outcomes in men versus women undergoing CABG [96]. Beyond these factors, specific pharmacologic and therapeutic considerations, such as the role of estrogen replacement therapy, need to be clarified. As further knowledge accumulates, it is hoped that gender-specific risk factors can be mitigated and protective factors exploited, thereby improving the outcomes for all cardiac surgery patients.

Cardiac Surgical Procedures↗
PubMed2003

Prevalence of risk factors, and not gender per se, determines short- and long-term survival after coronary artery bypass surgery.

OBJECTIVE: Much attention has been directed towards female gender as an independent risk factor for in-hospital mortality after coronary artery bypass grafting surgery; however, the effects of surgery are known to persist for 6 months or more. Studies that have compared postoperative survival in women and men beyond hospital discharge report disparate results with regard to the independent effect of gender per se on ultimate survival. DESIGN: This investigation was a prospective, observational study. SETTING: The study was a multicenter investigation involving 24 US medical centers. PARTICIPANTS: There were 2,048 patients undergoing isolated coronary artery bypass graft surgery enrolled between September 1991 and September 1993 and after discharge. INTERVENTIONS: There were no interventions with this prospective observational study. MEASUREMENTS AND MAIN RESULTS: Preoperative demographic variables, medical history, and angiographic data were collected for each patient at the time of enrollment. Patients' vital status through the National Death Index up to August 31, 1998, were added to assess postoperative long-term survival. For survivorship analysis, the Kaplan-Meier product-limit method was used with Cox regression model. Survivorship analyses were performed separately and in combination on mortality within 30 days and 6 months of coronary artery bypass graft surgery and during the entire postoperative follow-up period. Among women, preoperative disease status, as expected, was more severe than that in men. Women were older (p = 0.0001) and had more comorbidity, such as congestive heart failure (p = 0.0019), diabetes (p = 0.0001), anemia, and hypertension (p = 0.0001). After surgery, unadjusted survival of 6 months and 5 years in women was worse than that in men. However, there were no gender-related differences in short- or long-term survival after adjusting for covariates in the multivariate model. Preoperative conditions, such as congestive heart failure, anemia, diabetes, and advanced age, are indicative of greater risk in both women and men for lower survival after coronary artery bypass graft surgery. CONCLUSIONS: Disease prevalence in women, and not gender per se, affects mid- and long-term survival after cardiac surgery. Attention, therefore, should be focused on efforts to reduce or modify such disease prevalence earlier in women, which may in turn allow longer survival after surgical intervention. Differences in postoperative survival between women and men were related to the gender differences in the distribution of preoperative risk factors.

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