Christian T. Campos

Disease-free intervals after partial ileal bypass in patients with coronary heart disease and hypercholesterolemia: report from the Program on the Surgical Control of the Hyperlipidemias (POSCH)☆

OBJECTIVESnWe sought to analyze the disease-free intervals and calculate the freedom from atherosclerosis events in the Program on the Surgical Control of the Hyperlipidemias (POSCH).nnnBACKGROUNDnThe POSCH study was a randomized, secondary lipid/atherosclerosis intervention trial that provided strong evidence for reduction in atherosclerosis progression as demonstrated by clinical and arteriographic end points. The 417 control group patients received American Heart Association phase II diet instruction, and the 421 intervention group patients received identical dietary instruction and underwent a partial ileal bypass operation.nnnMETHODSnFour outcome measures were determined: 1) overall mortality, 2) coronary heart disease mortality, 3) coronary heart disease mortality and confirmed nonfatal myocardial infarction, and 4) coronary/cardiac interventions.nnnRESULTSnAn overall mortality rate of 10% occurred at 6.7 years in the control group and 9.4 years in the intervention group, for a gain in disease-free interval of 2.7 years in the intervention group (p = 0.032). A coronary heart disease mortality rate of 8% occurred at 7.2 years in the control group and 11 years in the intervention group, for a gain of 3.8 years (p = 0.046). Twenty percent of patients demonstrated the combined end point of coronary heart disease mortality and confirmed nonfatal myocardial infarction at 5.9 years in the control group and 11.4 years in the intervention group, for a gain of 5.5 years (p < 0.001). Twenty-five percent of patients underwent either coronary artery bypass graft surgery, percutaneous transluminal coronary angioplasty or heart transplantation at 5.4 years in the control group and 12.4 years in the intervention group, for a gain of 7 years (p < 0.001).nnnCONCLUSIONSnThe marked lipid modification achieved by partial ileal bypass in the POSCH trial led to demonstrable increases in the disease-free intervals for overall mortality, coronary heart disease mortality, coronary heart disease mortality and confirmed nonfatal myocardial infarction, and coronary intervention procedures. For the clinician and the patient, estimation of disease-free intervals may be more relevant than assessment of differences in incidence rates and risk ratios.

Spiral CT With Multiplanar and Three-Dimensional Reconstructions Accurately Predicts Tracheobronchial Pathology

BACKGROUNDnThis study was designed to evaluate the clinical accuracy of multiplanar reconstructions and three-dimensional shaded surface displays compared with conventional transaxial computed tomography, bronchoscopy, and surgical pathologic findings.nnnMETHODSnTransaxial computed tomographic images, two-dimensional nonstandard multiplanar reconstruction images, and three-dimensional images obtained from patients with tracheobronchial disease were prospectively evaluated for the relationship to adjacent structures, lesion characterization, and surgical anatomic correlation before invasive procedures.nnnRESULTSnCompared with conventional transaxial computed tomographic images, multiplanar reconstructions and three-dimensional shaded surface displays provided a correlative map of bronchoscopic and surgical anatomy in patients with benign and malignant tracheobronchial pathology. The longitudinal extent of abnormalities are better demonstrated on the multiplanar reconstruction and three-dimensional images, whereas the transverse extent of disease and relationships to adjacent structures were better shown on axial computed tomographic sections.nnnCONCLUSIONSnThree-dimensional and multiplanar two-dimensional images are additive to transaxial computed tomography for evaluation of diseases involving the central airways. They are beneficial for planning invasive procedures. More importantly, they provide consistent, highly accurate measurements for routine follow-up and for future clinical trials.

Predictors of 30-day hospital readmission after coronary artery bypass

BACKGROUNDnRisk factors for 30-day hospital readmission following coronary artery bypass grafting (CABG) have not been established.nnnMETHODSnWe prospectively followed 485 consecutive patients who underwent isolated primary CABG at our institution in 1997. Patients were contacted by telephone at 30 days following operation to determine readmission status.nnnRESULTSnThe overall readmission rate was 16% (76 of 485). Female gender (25% versus 11%, p = 0.001) and diabetes (22% versus 12%, p = 0.005) were associated with significantly higher readmission rates. The relationship between female gender and readmission persisted after correcting for age and other comorbidities. Congestive heart failure trended towards a significant relationship with increased readmission rate (22% versus 14%, p = 0.09). There were no significant associations between 30-day readmission rate and age, hypertension, chronic obstructive pulmonary disease, history of myocardial infarction, peripheral vascular disease, creatinine level of > or = 1.4 mg/dL, or decreased left ventricular ejection fraction (< 40%).nnnCONCLUSIONSnThese data show that most of the classic risk factors for postoperative mortality are not necessarily associated with increased readmission. However, female gender and diabetes are associated with greater than twice the risk of 30-day readmission following CABG.

Central Venous Catheter Use in Low-Risk Coronary Artery Bypass Grafting

BACKGROUNDnTo assess the impact of central venous pressure catheter monitoring in low-risk coronary artery bypass grafting (CABG), we compared the hospital course of patients undergoing CABG with central venous pressure catheter monitoring with that of similar patients undergoing CABG with pulmonary artery catheter monitoring.nnnMETHODSnAll isolated primary CABG procedures (n = 312) performed between April 22 and October 31, 1996, were evaluated, and 194 patients meeting six central venous pressure catheter use criteria were identified. Of these 194 patients, 133 (68%) underwent CABG with central venous pressure catheter monitoring, and 61 (32%) had pulmonary artery catheter monitoring owing to surgeon or anesthesiologist preference.nnnRESULTSnIn-hospital mortality was similar. A trend toward increased overall complications was seen in the pulmonary artery catheter group. The total volume infused in the first 12 hours, the 24-hour weight gain, and the intubation time were significantly greater in the pulmonary artery catheter group. Increases in intensive care unit length of stay and in total hospital charges trended toward statistical significance in the pulmonary artery catheter group.nnnCONCLUSIONSnPulmonary artery catheter use in low-risk patients undergoing CABG was associated with greater weight gain and longer intubation time and may be associated with increased morbidity and utilization of hospital resources.

Gender and functional outcome after coronary artery bypass.

BACKGROUNDnFemale gender is an established risk factor for increased mortality and morbidity after coronary artery bypass graft (CABG) surgery. However, the impact of gender on functional outcome after CABG is not well established.nnnMETHODSnFunctional status was assessed at baseline and at 6 months with the Duke Activity Status Index (DASI) in 196 consecutive patients undergoing isolated primary CABG. Follow-up data were complete in 158 (81%) patients. The functional status of the 54 (34%) female and the 104 (66%) male patients was compared.nnnRESULTSnThe mean DASI score was significantly lower in women at baseline (19.3 +/- 13.8 vs 28.3 +/- 16.8, P = .001) and at 6 months (22.7 +/- 16.3 vs 32.8 +/- 18.2, P = .0007); however, the 6-month change in DASI score (3.3 +/- 16.9 vs 4.5 +/- 20.0, P = .7) was comparable. A similar proportion of women and men (54% vs 53%) had improved above their baseline functional level at 6 months.nnnCONCLUSIONSnThese data demonstrate that women undergo CABG at a significantly lower functional level than men; however, the functional improvement after CABG is similar across genders.

Mitochondrial DNA deletions in coronary artery bypass grafting patients

OBJECTIVEnMitochondrial DNA (mitoDNA) deletions have been shown to increase with aging and ischemia and have been suggested to contribute to myocardial dysfunction. The purpose of this study was to determine the prevalence and specificity of mitoDNA deletions in coronary artery bypass patients.nnnMETHODSnRight atrial appendix tissue from 51 cardiac surgical patients (30-93 years; mean 64+/-14 years) was obtained during cardiopulmonary bypass cannulation (Control), just prior to the removal of the venous cannula (Ischemia, 169+/-38 min) and following removal of the cannula (Reperfusion) and used for polymerase chain reaction (PCR) and sequence analysis.nnnRESULTSnA novel mitoDNA deletion (approximately 7.3 kb, mitoDNA(7.3)) was found in three unrelated, male patients (53, 67, 75 years old). All mitoDNA(7.3) deletion breakpoints were found downstream of the ATP synthase 8 genes and at the 3 end of the cytochrome b genes. The prevalence of the mitoDNA(7.3) deletion was significantly increased (P<0.05) following ischemia and reperfusion. Clinical data indicated that postoperative left ventricular ejection fraction was lower (38.3 vs. 46.4%), and the incidence of previous myocardial infarction higher (1.7 vs. 0.6) in patients exhibiting mitoDNA deletions.nnnCONCLUSIONnOur results reveal a novel mitochondrial DNA deletion occurring within the genome region coding for the mitochondrial genes of oxidative phosphorylation that is significantly increased during ischemia and reperfusion. The incidence and prevalence of mitoDNA(7.3) deletions in patients with clinical indications of poor recovery suggests that mitoDNA(7.3) deletions may provide an important indicator to surgical outcome in the cardiac surgical patient.

Effect of aspirin use on death and recurrent myocardial infarction in current and former cigarette smokers

The purpose of this study was to examine the effects of aspirin use on mortality and morbidity rates in a subset of the control group of the Program on the Surgical Control of the Hyperlipidemias (POSCH) that was stratified by cigarette smoking status at the time of randomization. The clinical impact of aspirin intake in cigarette smokers and former cigarette smokers has not been well studied. POSCH was a randomized, controlled, clinical trial designed to ascertain the effects of lipid modification by the partial ileal bypass operation on clinical end-points and arteriographic changes in postmyocardial infarction subjects with hypercholesterolemia. Cohorts of cigarette smokers in the diet-control group were evaluated for overall and atherosclerotic coronary heart disease (ACHD) mortality rates and recurrent confirmed nonfatal myocardial infarction rates. In current cigarette smokers at baseline (n = 90) with a mean follow-up of 8.3 years, the overall mortality rate was 45.2% in patients with no aspirin use and 10.4% in patients who reported even infrequent aspirin use (relative risk = 4.3, 95% confidence interval (CI) = 2.4 to 10.6, p < 0.001). For ACHD mortality in this cohort, the relative risk was 17.1 (35.7% vs 2.1%, 95% CI = 1.4 to 125.0, p < 0.001); for the combined end-point of ACHD mortality and nonfatal myocardial infarction, the relative risk was 2.4 (40.5% vs 16.7%, 95% CI = 1.2 to 5.1, p = 0.018).(ABSTRACT TRUNCATED AT 250 WORDS)

Myocardial infarction and percent arteriographic stenosis of culprit lesion: report from the Program on the Surgical Control of the Hyperlipidemias (POSCH).

The objective of this study was to assess the percent stenosis of the culprit lesion responsible for subsequent myocardial infarction in the Program on the Surgical Control of the Hyperlipidemias (POSCH). It is unknown if the susceptible coronary artery culprit lesion responsible for an acute myocardial infarction is relatively large ( > or = 50% arteriographic stenosis) and hemodynamically significant ( > or = 70% stenosis), or small ( < 50%, stenosis) and asymptomatic. Certain necropsy and arteriography studies support the large progenitor lesion concept, and other arteriography studies support the small lesion hypothesis. We analyzed the coronary arteriogram immediately preceding a Q wave (transmural) myocardial infarction for the degree of stenosis of the suspected culprit lesion, which was selected by visual inspection of the coronary circulation supplying the electrocardiogram-defined area of myocardial infarction. There was no perceptible difference with respect to vessel segment distribution of culprit lesions or time to infarction between the 52 control-group patients and the 27 intervention-group patients. For the two groups combined (n=79), the predominantly involved segments were the middle right coronary artery and the proximal left anterior descending coronary artery. The time interval from the preceding coronary arteriogram closest to the index myocardial infarction ranged from 0 days to 10 years; however, 64.6% of the arteriograms were performed 2 years or less prior to the myocardial infarction. Only 5.1% of the patients in both groups combined had a culprit lesion stenosis < 50%, while 88.6% of the patients in both groups combined had a culprit lesion stenosis > or = 70%. The results strongly favor the large lesion hypothesis of causation for myocardial infarction. It is premature, however, to state that the relative size of the culprit lesion has been indisputably determined. The resolution of this problem has exceedingly important practical implications for the management of patients with known atherosclerotic coronary heart disease and for those asymptomatic individuals with silent atherosclerotic coronary heart disease.

Program on the surgical control of the hyperlipidemias: 1994 report

The Program on the Surgical Control of the Hyperlipidemias (POSCH), a randomized clinical trial, tested the hypothesis that cholesterol modification induced by partial ileal bypass would favorably affect mortality and morbidity due to coronary heart disease (CHD). The study population consisted of 838 patients (417 in the control group and 421 in the surgery group) in four clinical centers, both men (90.7%) and women with an average age of 51 years who had survived a first myocardial infarction. The lipid changes in POSCH have been the most marked in any atherosclerosis intervention trial utilizing a single mode of intervention in addition to diet therapy. At 5 years, the surgery group, compared with the control group, had a 23.3 ± 1.0% (mean ± SE) lower total plasma cholesterol level (p < 0.0001), a 37.7 < 1.2% lower low-density lipoprotein cholesterol level (p < 0.0001), and a 4.3 ± 1.8% higher high-density lipoprotein cholesterol level (p = 0.02). For the combined end point of CHD mortality and confirmed nonfatal myocardial infarction, there was a 35.0% reduction in the surgery group (p < 0.001). Coronary artery bypass grafting was reduced in the surgery group by 62.0% (p < 0.0001) and percutaneous transluminal coronary angioplasty was reduced by 55.0% (p < 0.01). A comparison of baseline coronary arteriograms with those obtained at 3, 5, 7, and 10 years consistently showed less atherosclerosis disease progression (p < 0.001) and greater atherosclerosis disease regression at 5 and 7 years (p < 0.01) in the surgery group. At formal trial completion in July 1990, the overall mortality in the surgery subgroup with an ejection fraction of 50% or greater was 36.1% lower (p = 0.02). During subsequent follow-up, trends toward statistical significance for differences in both CHD and in overall mortality have become evident. The POSCH results provide strong support for beneficial clinical and arteriographie reduction of atherosclerosis progression after lipid modification by partial ileal bypass.

Control of Risk Factors in Atherosclerosis POSCH Reporta

This report is a summary of the methods and results of the Program on the Surgical Control of the Hyperlipidemias (POSCH) through formal trial completion on July 19, 1990 and the continued follow-up of patients until September of 1992. Much of this material has been published previously, including detailed descriptions of the POSCH design and methodology, patient baseline characteristics,2 recruitment experience,3 lipid clinical results.8 arteriographic analyses,x,y correlation of changes in sequential arteriograms with clinical end points,IO quality of life assessments, and findings in women. l 2 Currently undergoing review are papers on the POSCH subgroup analysis and an assessment of the results in terms of diseasefree intervals in this trial.