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)

Objectives. We sought to analyze the disease free intervals and calcul ate the freedom from atherosclerosis events in the Program on the Surg ical Control of the Hyperlipidemias (POSCH). Background. The POSCH stu dy was a randomized, secondary lipid/atherosclerosis intervention tria l that provided strong evidence for reduction in atherosclerosis progr ession as demonstrated by clinical and arteriographic end points. The 417 control group patients received American Heart Association phase I I diet instruction, and the 421 intervention group patients received i dentical dietary instruction and underwent a partial ileal bypass oper ation. Methods. Four outcome measures were determined: 1) overall mort ality, 2) coronary heart disease mortality, 3) coronary heart disease mortality and confirmed nonfatal myocardial infarction, and 4) coronar y/cardiac interventions. Results. An overall mortality rate of 10% occ urred at 6.7 years in the control group and 9.4 years in the intervent ion group, for a gain in disease-free interval of 2.7 years in the int ervention group (p = 0.032). A coronary heart disease mortality rate o f 8% occurred at 7.2 years in the control group and 11 years in the in tervention group, for a gain of 3.8 years (p = 0.046). Twenty percent of patients demonstrated the combined end point of coronary heart dise ase mortality and confirmed nonfatal myocardial infarction at 5.9 year s 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 underw ent either coronary artery bypass graft surgery, percutaneous translum inal 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). Conclusions. The marked lipid modification achie ved by partial ileal bypass in the POSCH trial led to demonstrable inc reases in the disease-free intervals for overall mortality, coronary h eart 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 interva ls may be more relevant than assessment of differences in incidence ra tes and risk ratios.