Biomedical subjects

S Khuri

Publications and source records attributed to S Khuri.

At least 19 recordsLinked to original sources

PubMed2001

Hysterectomy in Veterans Affairs Medical Centers.

OBJECTIVE: To examine the indications and surgical morbidity for women veterans who underwent hysterectomies in Department of Veterans Affairs Medical Centers (VAs). METHODS: Data on hysterectomies performed in VAs from 1991 to 1997 were abstracted from a surgical quality improvement program. RESULTS: Records of 1722 women who had hysterectomies in VAs over 6 years were examined. Women were predominately white (62%) and their average age was 42.5 years. Operations included abdominal (74%), vaginal (22%), and laparoscopic-assisted (4%) methods. The most common indications for surgery included uterine leiomyomas (31%), abnormal uterine bleeding (14%), and endometriosis (11%). Indications differed by race (P <.01); nonwhite women were most likely to have surgery for leiomyoma (51%), whereas white women had hysterectomies for leiomyomas (19%), abnormal bleeding (15%), endometriosis (13%), and genital prolapse (11%). The mean postoperative stay was significantly longer for abdominal hysterectomies (4.51 days) than either vaginal or laparoscopic-assisted hysterectomies (2.92 and 2.21 days, respectively; P <.001). The overall complication rate within 30 days was 9%, and the most frequent complication was urinary tract infection (3.3%). CONCLUSION: Women who underwent hysterectomies in VAs had low complication rates, comparable to hysterectomy complication rates in the United States generally.

Adult↗

PubMed2001

Postoperative and late survival outcomes after major amputation: findings from the Department of Veterans Affairs National Surgical Quality Improvement Program.

BACKGROUND: A surgical risk model is used to analyze postoperative mortality and late survival for older veterans who underwent above- or below-knee amputations in 119 Veterans Affairs (VA) hospitals from 1991 to 1995. METHODS: Preoperative medical conditions and laboratory values abstracted by the VA National Surgical Quality Improvement Program were linked to subsequent hospitalization and survival through 1999. Logistic regression and proportional hazards models were used to develop risk indexes for postoperative mortality and long-term survival. RESULTS: Thirty-day postoperative mortality was 6.3% for 1909 below-knee and 13.3% for 2152 above-knee amputees. Mortality varied greatly between the lowest-highest risk index quartiles (0.8%-18.4% for below-knee amputation and 2.3%-31.1% for above-knee amputation). Surviving patients had 10,827 subsequent VA hospitalizations during a median 32-month follow-up. Survival probabilities for below- and above-knee amputees were 77% and 59% at 1 year, 57% and 39% at 3 years, and 28% and 20% at 7.5 years. The lowest quartile of survival risk had a 61% five-year survival compared with 14% for the highest-risk quartile. CONCLUSION: A generic surgical risk model can be of use in stratifying prognosis after major amputation. The heavy burden of hospital use by these patients suggests the need for better disease management for this high-risk, high-cost patient population.

Adult↗

PubMed2001

Postoperative and amputation-free survival outcomes after femorodistal bypass grafting surgery: findings from the Department of Veterans Affairs National Surgical Quality Improvement Program.

PURPOSE: A noncardiac surgery risk model was used as a means of analyzing variations in postoperative mortality and amputation-free survival for older veterans undergoing femorodistal bypass grafting surgery. METHODS: A prospective cohort study was undertaken in 105 Veterans Affairs (VA) hospitals at the time of index operation from 1991 to 1995. Each patient was linked to subsequent hospitalizations, major amputation surgery, and survival through 1999. Logistic regression and proportional hazards models were used as a means of developing risk indices on the basis of risk factors from the VA National Surgical Quality Improvement Program. A total of 4288 male veterans 40 years or older underwent artificial, vein, or in situ bypass grafting surgery at the femoral to tibial level. The main outcome measures were 30-day postoperative mortality and amputation-free survival. RESULTS: Approximately half of all patients had undergone an earlier revascularization or amputation at any level for vascular disease. The 30-day postoperative mortality rate was 2.1% and varied greatly between mortality risk index quartiles (0.6%-5.2%). In a median 44.3 months of follow-up, surviving patients had 17,694 subsequent VA hospitalizations, 1147 patients (26.7%) underwent subsequent major amputation, and 1913 patients (44.6%) died. The overall survival probability was 88% at 1 year and 63% at 5 years; 1- and 5-year (any sided) limb salvage rates were 87% and 74%, respectively, for patients who underwent a femoropopliteal bypass grafting procedure, compared with 77% and 63%, respectively, for patients who underwent a tibial bypass grafting procedure. When amputation and death were combined as end points, amputation-free survival probability rates at 1, 3, and 7.5 years were 74%, 56%, and 29%, respectively. Patients with the best 20% survival risk scores had observed mean survival probability rates 30% higher than patients in the poorest 20% of survival risk. CONCLUSION: Risk indices derived from the preoperative workup may be of use to clinicians in assessing and communicating risk and prognosis. Risk-adjustment of outcomes is critical for evaluating future disease management initiatives for patients with advanced peripheral arterial disease.

Aged↗

PubMed2001

Validating risk-adjusted surgical outcomes: chart review of process of care.

OBJECTIVE: The primary purpose of this study was to validate risk-adjusted surgical outcomes as indicators of the quality of surgical care at US Department of Veterans Affairs (VA) hospitals. The secondary purpose was to validate the risk-adjustment models for screening cases for quality review. DESIGN: We compared quality of care, determined by structured implicit chart review, for patients from hospitals with higher and lower than expected operative mortality and morbidity (hospital-level tests) and between patients with high and low predicted risk of mortality and morbidity who died or developed complications (patient-level tests). SUBJECTS: 739 general, peripheral vascular and orthopedic surgery cases sampled from the 44 VA hospitals participating in the National VA Surgical Risk Study. MAIN OUTCOME MEASURES: A global rating of quality of care based on chart review. RESULTS: Ratings of overall quality of care did not differ significantly between patients from hospitals with higher and lower than expected mortality and morbidity. On some of the secondary measures, patient care was rated higher for hospitals with lower than expected operative mortality. At the patient level of analysis, those who died or developed complications and had a high predicted risk of mortality or morbidity were rated higher on quality of care than those with a low predicted risk of adverse outcome. CONCLUSIONS: The absence of a relationship between most of our measures of process of care and risk-adjusted outcomes may be due to an insensitivity of chart reviews to hospital-level differences in quality of care. Site visits to National VA Surgical Risk Study hospitals with high and low risk-adjusted mortality and morbidity have detected differences on a number of dimensions of quality. The patient-level findings suggest that the risk-adjustment models are useful for screening adverse outcome cases for quality of care review.

Data Interpretation, Statistical↗

PubMed2001

Phylogeny, function, and evolution of the cupins, a structurally conserved, functionally diverse superfamily of proteins.

The cupin superfamily is a group of functionally diverse proteins that are found in all three kingdoms of life, Archaea, Eubacteria, and Eukaryota. These proteins have a characteristic signature domain comprising two histidine- containing motifs separated by an intermotif region of variable length. This domain consists of six beta strands within a conserved beta barrel structure. Most cupins, such as microbial phosphomannose isomerases (PMIs), AraC- type transcriptional regulators, and cereal oxalate oxidases (OXOs), contain only a single domain, whereas others, such as seed storage proteins and oxalate decarboxylases (OXDCs), are bi-cupins with two pairs of motifs. Although some cupins have known functions and have been characterized at the biochemical level, the majority are known only from gene cloning or sequencing projects. In this study, phylogenetic analyses were conducted on the conserved domain to investigate the evolution and structure/function relationships of cupins, with an emphasis on single- domain plant germin-like proteins (GLPs). An unrooted phylogeny of cupins from a wide spectrum of evolutionary lineages identified three main clusters, microbial PMIs, OXDCs, and plant GLPs. The sister group to the plant GLPs in the global analysis was then used to root a phylogeny of all available plant GLPs. The resulting phylogeny contained three main clades, classifying the GLPs into distinct subfamilies. It is suggested that these subfamilies correlate with functional categories, one of which contains the bifunctional barley germin that has both OXO and superoxide dismutase (SOD) activity. It is proposed that GLPs function primarily as SODs, enzymes that protect plants from the effects of oxidative stress. Closer inspection of the DNA sequence encoding the intermotif region in plant GLPs showed global conservation of thymine in the second codon position, a character associated with hydrophobic residues. Since many of these proteins are multimeric and enzymatically inactive in their monomeric state, this conservation of hydrophobicity is thought to be associated with the need to maintain the various monomer- monomer interactions. The type of structure-based predictive analysis presented in this paper is an important approach for understanding gene function and evolution in an era when genomes from a wide range of organisms are being sequenced at a rapid rate.

Amino Acid Sequence↗

PubMed2000

Microbial relatives of the seed storage proteins of higher plants: conservation of structure and diversification of function during evolution of the cupin superfamily.

This review summarizes the recent discovery of the cupin superfamily (from the Latin term "cupa," a small barrel) of functionally diverse proteins that initially were limited to several higher plant proteins such as seed storage proteins, germin (an oxalate oxidase), germin-like proteins, and auxin-binding protein. Knowledge of the three-dimensional structure of two vicilins, seed proteins with a characteristic beta-barrel core, led to the identification of a small number of conserved residues and thence to the discovery of several microbial proteins which share these key amino acids. In particular, there is a highly conserved pattern of two histidine-containing motifs with a varied intermotif spacing. This cupin signature is found as a central component of many microbial proteins including certain types of phosphomannose isomerase, polyketide synthase, epimerase, and dioxygenase. In addition, the signature has been identified within the N-terminal effector domain in a subgroup of bacterial AraC transcription factors. As well as these single-domain cupins, this survey has identified other classes of two-domain bicupins including bacterial gentisate 1, 2-dioxygenases and 1-hydroxy-2-naphthoate dioxygenases, fungal oxalate decarboxylases, and legume sucrose-binding proteins. Cupin evolution is discussed from the perspective of the structure-function relationships, using data from the genomes of several prokaryotes, especially Bacillus subtilis. Many of these functions involve aspects of sugar metabolism and cell wall synthesis and are concerned with responses to abiotic stress such as heat, desiccation, or starvation. Particular emphasis is also given to the oxalate-degrading enzymes from microbes, their biological significance, and their value in a range of medical and other applications.

Amino Acid Motifs↗

PubMed1999

Racial variation in the use of laparoscopic cholecystectomy in the Department of Veterans Affairs medical system.

BACKGROUND: While studies have found racial differences in the rates of use of established invasive cardiac and cerebrovascular procedures, no study has evaluated racial variation in the rates of adoption of new surgical procedures. For patients undergoing laparoscopic cholecystectomy, the procedure represents a new and safe option that shortens the duration of postoperative hospitalization by almost one week. In this study, we evaluated whether, in the equal access Veterans Affairs (VA) medical system, the rate of adoption of this procedure and improvements in the duration of postoperative hospitalization differed between African-American and Caucasian patients. STUDY DESIGN: Data were obtained from two sources-administrative claims files and prospectively compiled dinical data from medical records and patient interviews. In both data sets, frequency of use, length of stay, and outcomes for African-American and Caucasian patients undergoing minimally invasive and open gallbladder surgery were analyzed for the first four years of use of the procedure in the VA system (1992 to 1995). RESULTS: Analyses based on claims files indicated that, after adjustment for potentially confounding variables, African-American patients who underwent cholecystectomy in VA medical centers were 25% less likely to undergo a minimally invasive cholecystectomy during the first 4 years of use of the new procedure (adjusted odds ratio, 0.74; 95% confidence interval, 0.66-0.83). Shortening of the average postoperative length of stay from 9 days or more in the prelaparoscopic era to less than 4.5 days for patients undergoing the laparoscopic procedure occurred in the first year for Caucasian patients, but did not occur until the fourth year for African-American patients (p<0.001). The overall difference in postoperative length of stay between African-American and Caucasian patients more than doubled from 1.7 days before introduction of laparoscopic cholecystectomy to 3.8 days in the fourth year. In comparison, analyses based on nurse-compiled clinical data indicated that, after adjustment for relevant clinical factors, racial variations in the rate of laparoscopic surgery were even larger (adjusted odds ratio for laparoscopic versus open cholecystectomy for African-American versus Caucasian veterans, 0.68; 95% confidence interval, 0.55-0.84). CONCLUSIONS: Compared to Caucasian patients, African-American patients who underwent cholecystectomy in VA medical centers had an approximately 25% to 32% lower likelihood of undergoing minimally invasive cholecystectomy procedures. The differences in rates of adoption of laparoscopic surgery did not appear to be from more comorbid illnesses among African-American patients. African-American and Caucasian veterans may differ in their preference for new surgical procedures like laparoscopic cholecystectomy. Conversely, VA physicians may have been less likely to recommend laparoscopic cholecystectomies to African-American patients.

Adult↗

PubMed1999

Adenosine myocardial protection: preliminary results of a phase II clinical trial.

OBJECTIVE: To evaluate the safety, tolerance, and efficacy of adenosine in patients undergoing coronary artery bypass surgery. SUMMARY BACKGROUND DATA: Inadequate myocardial protection in patients undergoing coronary artery bypass surgery contributes to overall hospital morbidity and mortality. For this reason, new pharmacologic agents are under investigation to protect the regionally and globally ischemic heart. METHODS: In a double-blind, placebo-controlled trial, 253 patients were randomized to one of three cohorts. The treatment arms consisted of the intraoperative administration of cold blood cardioplegia, blood cardioplegia containing 500 microM adenosine, and blood cardioplegia containing 2 mM adenosine. Patients receiving adenosine cardioplegia were also given an infusion of adenosine (200 microg/kg/min) 10 minutes before and 15 minutes after removal of the aortic crossclamp. Invasive and noninvasive measurements of ventricular performance were obtained before, during, and after surgery. RESULTS: The high-dose adenosine cohort was associated with a trend toward a decrease in high-dose dopamine support and a lower incidence of myocardial infarction. A composite outcome analysis demonstrated that patients who received high-dose adenosine were less likely to experience one of five adverse events: high-dose dopamine use, epinephrine use, insertion of intraaortic balloon pump, myocardial infarction, or death. The operative mortality rate for all patients studied was 3.6% (9/253). CONCLUSIONS: Adenosine treatment is safe and well tolerated and may be associated with fewer postoperative complications.

Adenosine↗

PubMed1994

Clinical application of the forearm tourniquet.

We undertook this prospective study of 148 consecutive hand and wrist procedures to evaluate the safety and efficacy of the forearm tourniquet. Patients were assigned to three groups based on tourniquet pressure used, ranging from 50 to 125 mmHg above systolic blood pressure. The forearm tourniquet was well tolerated by all patients. No patient had neurologic complications. Minimal intraoperative bleeding occurred when the pressure was greater than 75 mmHg above systolic blood pressure. The forearm tourniquet is a safe and effective means of providing a bloodless field for wrist and hand surgery.

Forearm↗

PubMed1994

Long-term graft patency (3 years) after coronary artery surgery. Effects of aspirin: results of a VA Cooperative study.

BACKGROUND: The long-term success of coronary bypass surgery is dependent on graft patency after surgery. This trial was designed to determine if aspirin improved saphenous vein graft or internal mammary artery (IMA) graft patency between 1 and 3 years after coronary artery bypass grafting (CABG). METHODS AND RESULTS: After receiving aspirin 325 mg/d for 1 year after CABG and undergoing a 1-year postoperative cardiac catheterization, patients were randomized to receive either aspirin (325 mg) or placebo for 2 additional years. Angiography was performed 3 years after surgery to determine the primary end point-saphenous vein graft patency in 288 patients and IMA graft patency in 167 patients. At 3 years after CABG, the saphenous vein graft occlusion rate was 17.0% (62 of 365) for patients treated with aspirin compared with 19.7% (74 of 376) for those who received placebo (P = .404). For saphenous vein grafts that were patent at 1 year, the occlusion rate at 3 years was 4.8% (15 of 313) for patients treated with aspirin compared with 4.2% (13 of 310) for patients who received placebo (P = .757). At 3 years, the IMA graft occlusion rate was 10.3% (8 of 78) for patients treated with aspirin compared with 7.9% (7 of 89) for patients who received placebo (P = .594). For IMA grafts that were patent at 1 year, the occlusion rate was 4.3% (3 of 70) for patients treated with aspirin compared with 2.5% (2 of 81) for patients who received placebo (P = .541). CONCLUSIONS: These data suggest that aspirin treatment does not improve saphenous vein graft or IMA graft patency between 1 and 3 years after CABG.

Aspirin↗

PubMed1993

Acute and late radial collateral ligament injuries of the thumb metacarpophalangeal joint.

Eighteen patients were treated surgically for injuries to the radial collateral ligament of the thumb metacarpophalangeal joint. Late repairs were performed in 12 and immediate repairs in 6. At follow-up after a mean of 6 years, 94% of the patients were completely satisfied with the results. No patients had significant pain in their thumbs, and none were limited in work or avocational activities. A stable repair was maintained in all patients. There was no difference in grip or pinch strengths between the immediate and late groups. Loss of thumb motion in the late group (mean = 77% of normal) was slightly more than that in the immediate group (mean = 89% of normal). Late repair gives equally good subjective results and causes a slightly greater loss of thumb motion than immediate repair.

Acute Disease↗

PubMed1992

Changes in septal regional ejection fraction early and late following coronary artery bypass grafting in patients without postoperative myocardial infarction.

Changes in regional ejection fraction (rEF) of the interventricular septum following coronary artery bypass graft (CABG) surgery were examined using first-pass radionuclide ventriculography (RNVG) in patients without objective evidence of postoperative myocardial infarction (MI). One hundred and one patients had pre- (mean 6.3 days) and early postoperative (mean 8.7 days) RNVGs, and 60 of these patients had follow-up studies at 14-39 months (mean 27 months) postsurgery. Early post-CABG, mean rEF in the proximal septum was unchanged from the preoperative value (35.3%), with almost equal numbers of patients showing increased (n = 36), unchanged (n = 33) or decreased (n = 32) rEFs. In the distal septum, mean rEF increased from 47.1 to 50.7%, with more than twice as many patients having increased (n = 44) as decreased (n = 20) rEF. At late follow-up, proximal septum rEF in individual patients tended to revert to the presurgery baseline, with 72% (13/18) of regions with early decrease improved and 61% (14/23) of those with early improvement decreased. In the distal septum, rEF was less than early post-CABG in 76% (19/25) of patients with early improvement, while being improved in 27% (3/11) of those with early decrease in rEF. In the absence of MI, changes in rEF in the proximal septum early post-CABG tend to resolve over time. While global changes in cardiac systolic motion are the probable cause of many new post-CABG septal abnormalities, persistent septal dysfunction probably reflects effects of permanent damage as a result of the operative procedure.

Adult↗

PubMed1991

Starting aspirin therapy after operation. Effects on early graft patency. Department of Veterans Affairs Cooperative Study Group.

BACKGROUND: Although aspirin therapy started before operation improves vein graft patency after coronary artery bypass grafting, it also causes bleeding. The objective of this prospective, centrally directed, randomized, double-blind, placebo-controlled trial was to compare the effects of aspirin therapy started before operation with aspirin started 6 hours after operation on early (7-10-day) graft patency. METHODS AND RESULTS: Patients were randomized to receive either aspirin 325 mg or placebo the night before surgery; after operation, all patients received aspirin 325 mg daily, with the first dose administered through the nasogastric tube 6 hours after operation. Angiography was performed in 72% of the analyzed patients an average of 8 days after operation, and the primary end point was saphenous vein graft patency in 351 patients. Internal mammary artery graft patency was also assessed in 246 patients because many individuals received both internal mammary artery and vein grafts. In the patients given preoperative aspirin, the vein graft occlusion rate was 7.4 +/- 1.3% compared with 7.8 +/- 1.5% in those who received preoperative placebo (p = 0.871). In the subgroup of patients receiving Y grafts, 0.0% of the grafts were occluded in the preoperative aspirin group compared with 7.0 +/- 3.6% in the preoperative placebo group (p = 0.066). The internal mammary artery occlusion rate was 0.0% (0 of 131) in the aspirin group compared with 2.4 +/- 1.4% (three of 125) in the placebo group (p = 0.081). Patients in the aspirin group received more transfusions than those in the placebo group (median, 900 versus 725 ml, p = 0.006). The reoperation rate for bleeding in the aspirin group was 6.3% compared with 2.4% in the placebo group (p = 0.036). Median chest tube drainage within the first 6 hours after operation was 500 ml in the aspirin group compared with 448 ml in the placebo group (p = 0.011). CONCLUSIONS: Thus, preoperative aspirin is associated with increased bleeding complications and offers no additional benefit in early vein graft patency compared with starting aspirin therapy 6 hours after operation. There was a trend, although not significant, toward improved early patency for Y grafts and internal mammary artery grafts with preoperative aspirin.

Aged↗

PubMed1991

Significance of changes in resting left ventricular ejection fraction after coronary artery bypass grafting.

The prognostic significance of changes in resting left ventricular ejection fraction was examined in 102 patients who underwent successful coronary artery bypass grafting. Between preoperative and early postoperative radionuclide ventriculography, mean resting left ventricular ejection fraction improved from 47.2% to 53.9% (p less than 0.01). Left ventricular ejection fraction increased by 5% or greater in 64 patients (63%), remained unchanged (within 4%) in 31 (30%), and decreased by at least 5% in 7 (7%). During 14 to 39 months (mean 27 months) of clinical follow-up, patients with normal preoperative left ventricular ejection fraction had a lower prevalence of recurrent angina, congestive heart failure, and mortality resulting from cardiovascular disease. Cardiovascular morbidity and mortality occurred with equal frequency for patients who did and did not show early postoperative improvement in left ventricular ejection fraction (36% versus 39%). Among 69 patients who had a third radionuclide ventriculography at late follow-up, left ventricular ejection fraction was less than the early postoperative value in 69% and less than the preoperative result in 36%. Patients with early postoperative improvement in left ventricular ejection fraction were more likely to retain resting left ventricular contractile function, at least at the preoperative level (71% versus 46%).

Adult↗

PubMed1990

Perioperative myocardial infarction after coronary artery bypass surgery. Clinical significance and approach to risk stratification.

The clinical significance of perioperative myocardial infarction (MI) after coronary artery bypass surgery is not known. Therefore, strategies for the risk stratification of these patients do not exist. This study was undertaken to define the effect of perioperative MI on prognosis after discharge from the hospital and to develop an approach to the risk stratification of these patients. Fifty-nine patients with and 115 patients without perioperative MI were observed for 30 months for the development of cardiac events (death, nonfatal MI, and admission to hospital for unstable angina or congestive heart failure). Patients with perioperative MI were significantly more likely than patients without to have a cardiac event (31% versus 12%, p less than 0.01) and multiple events (19% versus 1%, p less than 0.001). Cox regression analysis identified two independent predictors of cardiac events other than perioperative MI (relative risk, 2.7): inadequate revascularization (relative risk, 3.5) and depressed (less than 40%) postoperative ejection fraction (EF) (relative risk, 2.1). Event-free survival rate of patients with perioperative MI varied markedly depending on the number of other negative prognostic variables present. Patients with perioperative MI who were adequately revascularized and had a postoperative EF greater than 40% had an event-free survival rate similar to patients without a perioperative MI (92% versus 87%, p = NS). Patients with perioperative MI who were inadequately revascularized and had depressed postoperative EF had an event-free survival rate of 13% (p less than 0.001 versus all other subsets). Event-free survival rate was intermediate (68%) in patients with perioperative MI and with only one of the other two variables (p less than 0.001 versus other subsets). In conclusion, perioperative MI adversely affects prognosis. Patients can be stratified into low, high, and intermediate risk subsets based on a simple assessment of the adequacy of revascularization and a determination of residual left ventricular function.

Coronary Artery Bypass↗

PubMed1990

Internal mammary artery and saphenous vein graft patency. Effects of aspirin.

As part of two Department of Veterans Affairs Cooperative Trials, we obtained angiographic patency data for internal mammary artery (IMA) and saphenous vein grafts to the left anterior descending (LAD) coronary artery at 1 year after coronary artery bypass surgery. Patients received either aspirin 325 mg q.d., aspirin 325 mg t.i.d., aspirin 325 mg and dipyridamole 75 mg t.i.d., or placebo. Aspirin was initiated either 12 hours before or 6 hours after operation. Patients were stratified preoperatively for extent of disease and randomized to the therapies outlined above. There was no randomization to IMA versus saphenous vein grafts to the LAD. When the patients taking placebo were compared with those taking aspirin, there were no differences in the IMA (100.0% versus 92.1%, p = 0.385) or vein graft (88.8% versus 90.4%, p = 0.675) patency rates. The patency rate, irrespective of treatment, for all IMA grafts was 92.8% (220 of 237) versus 90.1% (345 of 383) for all vein grafts to the LAD (p = 0.309). Thus, both the IMA and vein grafts had excellent patency rates at 1 year. Aspirin did not alter this at 1 year, and there were no differences between IMA and vein graft patency to the LAD.

Aspirin↗

PubMed1989

Intrathoracic pressures and left ventricular configuration with respiratory maneuvers.

In 12 dogs, we examined the correspondence between esophageal (Pes) and pericardial pressures over the anterior, lateral, and inferior left ventricular (LV) surfaces. Pleural pressure was decreased by spontaneous inspiration, Mueller maneuver, and phrenic stimulation and increased by intermittent positive pressure ventilation (IPPV) and positive end-expiratory pressure (PEEP). To separate effects due to blood flow, we analyzed beating and nonbeating hearts. In beating hearts, there were no significant differences between changes in Pes and pericardial pressures. In arrested hearts, increasing LV pressure by 8 Torr increased pericardial pressures by only 3.6 Torr. With IPPV and PEEP, increases in Pes and pericardial pressures were equal in live hearts and in low-volume arrested hearts (LV pressure = 4 Torr). In high-volume arrested hearts (LV pressure = 12 Torr), the increase in pericardial pressure over the anterior LV surface was less than Pes, whereas that over the lateral and inferior LV surfaces was the same as Pes. At high LV volume, in arrested hearts pericardial pressures decreased less than Pes during negative pressure maneuvers. In another six dogs, external LV configuration and volume were measured. In beating hearts during spontaneous inspiration, Mueller maneuver, and phrenic stimulation (endotracheal tube open), septal-lateral dimension and LV volume decreased by approximately 3% (P less than 0.05). This was also true for PEEP. In arrested hearts, septal-lateral dimension and LV volume decreased only with PEEP. We conclude that 1) the relationship between Pes and pericardial pressures is complex and depends on LV volume, local pericardial compliance, and the means by which Pes is changed, 2) changes in measured pericardial pressures did not completely explain changes in LV configuration, and 3) during different respiratory maneuvers, different forces account for the same observed changes in LV volume and configuration.

Animals↗

PubMed1989

Medical compared with surgical management of unstable angina. 5-year mortality and morbidity in the Veterans Administration Study.

We evaluated medical in comparison to surgical plus medical (surgical) treatment of unstable angina using a prospective randomized protocol that stratified patients by clinical presentation and by invasive evaluation of left ventricular (LV) function. Clinical presentations were as follows--type 1: progressive or new onset angina relieved by medication; type 2: prolonged bouts of angina poorly or incompletely relieved by medication. Abnormal LV function was arbitrarily defined as ejection fraction less than 0.50 or LV end-diastolic pressure 16 mm Hg or more. Of 468 patients, 237 were assigned to medical and 231 to surgical therapy. There were 374 type 1 and 94 type 2 patients. LV function was normal in 334 and abnormal in 134 patients. Compared with results at 24 months, this 60-month follow-up study showed important differences in survival for patients with three-vessel disease: 75% for medical and 89% for surgical patients (p less than 0.02). The cumulative 5-year rate of repeat hospitalizations for cardiac reasons was less with surgical patients for either clinical presentation. For type 1, medical patients had a 56% rate, and surgical patients had a 42% rate (p = 0.004). For type 2, medical patients had a 62% rate, and surgical patients had a 43% rate (p = 0.05). Overall mortality did not differ between the two treatments, and this remained true in type 1 versus type 2 patients and in those with normal versus abnormal LV function. However, regression analysis of medical and surgical groups with ejection fraction as a continuous variable showed that mortality of medical patients depended on ejection fraction (p = 0.004), whereas the mortality of surgical patients did not (p = 0.76), and survival in the surgical group was higher in the lowest ejection fraction tercile-73% for medical and 86% for surgical patients, p = 0.03. We conclude that surgery improves survival in patients with three-vessel disease and leads to fewer subsequent hospitalizations for cardiac reasons. An impaired ejection fraction had an adverse impact on survival of medical patients but not on surgical patients, and mortality in surgical patients was improved compared with medical patients in the lowest ejection fraction tercile.

Angina Pectoris↗