Cause of death analysis in the NHLBI PTCA Registry: results and considerations for evaluating long-term survival after coronary interventions.

Abstract

We examined cause of death in relation to age, length of follow-up and other baseline characteristics in patients in the 1985-1986 National Heart, Lung, and Blood Institute Percutaneous Transluminal Coronary Angioplasty (NHLBI PTCA) Registry. The manner in which cardiac versus noncardiac mortality of patients with coronary revascularization varies in relation to patient and study characteristics has not been well documented. Cause of death determined from a review of 5 years of annual follow-up forms and death certificates was analyzed in 2,127 patients who had coronary angioplasty (mean age 57.6 years) without acute myocardial infarction. Within 5 years of the initial procedure, there were 205 deaths (9.6%), with 52.7% attributed to cardiac causes. Patients with a low baseline ejection fraction, history of hypertension, previous bypass surgery, previous myocardial infarction, inoperable or high surgical risk or multivessel disease had significantly higher 5-year cardiac mortality. Patients with a history of diabetes, congestive heart failure or severe concomitant noncardiac disease had higher rates of both cardiac and noncardiac mortality. As length of follow-up increased, older patients died of noncardiac causes more often than cardiac causes. Age > or = 65 years was a strong independent predictor of 5-year noncardiac mortality (p < 0.001), but not cardiac mortality (p = 0.08). All-cause mortality rates may be high in elderly revascularized patients, yet cardiac mortality may be less than that expected because of a high risk of noncardiac death. Although all-cause mortality is a more reliable end point than cause-specific mortality, both cardiac and all-cause mortality should be considered in coronary intervention studies involving older patients and long-term follow-up.