ORLANDO, FLA. — Nearly half of patients hospitalized for acute coronary syndrome at one large HMO were rehospitalized for cardiovascular disease within the next 12 months, Stephen Sidney, M.D., reported at the annual meeting of the American College of Cardiology.
Within 12 months, 29% of the patients were readmitted for acute coronary syndrome (ACS). Adding in admissions for other manifestations of coronary heart disease along with those for heart failure and stroke, a total of 46% of patients were rehospitalized for cardiovascular disease (CVD) within 12 months of their index hospitalization for ACS.
Nearly 10% of patients were rehospitalized for coronary revascularization via coronary artery bypass graft surgery, and 7.4% were admitted for percutaneous intervention.
One-year mortality following the index hospitalization for ACS was 17.2%, and nearly two-thirds of the deaths were attributed to CVD, added Dr. Sidney of Kaiser Permanente in Oakland, Calif.
Few data are available on 1-year outcomes after hospital discharge for ACS, so Dr. Sidney and his coinvestigators analyzed computerized records for 14,852 patients admitted for ACS to Kaiser Permanente of Northern California hospitals during 1999-2000. The hospitalization rate for ACS was 5.7 cases per 1,000 person-years among subscribers to the prepaid health plan, which provides coverage to 30% of the population in the San Francisco Bay Area.
At the index ACS hospitalization, 31% of patients were hypertensive, 35% were diabetic, and 28% were hyperlipidemic. The relationships between these risk factors and the risks of rehospitalization for unstable angina and acute MI, respectively, differed in intriguing ways. For example, in a multivariate analysis, hyperlipidemic patients were 40% more likely to be rehospitalized for unstable angina within 12 months than were nonhyperlipidemic patients, but they were 32% less likely to experience MI.
In contrast, hypertension was associated with a 14% increased risk of rehospitalization for unstable angina but no significantly increased risk of rehospitalization for MI. Patients aged 65 or older were 16% more likely than were younger ACS patients to be rehospitalized for MI, but 12% less likely to be rehospitalized for unstable angina.
Diabetic patients had a 26% greater likelihood of being rehospitalized for MI and a 14% increased risk of rehospitalization for unstable angina compared with nondiabetics.
The Kaiser study was funded by Eli Lilly & Co.