Author + information
- Received November 2, 1989
- Revision received February 13, 1990
- Accepted March 13, 1990
- Published online August 1, 1990.
- John T. Rivers, MB, BS,
- Harvey D. White, MB, ChB, FACC∗,
- David B. Cross, MB, BS,
- Barbara F. Williams, RN and
- Robin M. Norris, MD
- ↵∗Address for reprints: Harvey D. White, MB, ChB, Green Lane Hospital, Auckland 3, New Zealand.
A group of 456 consecutive patients seen ≤ 6 h after the onset of acute myocardial infarction associated with ST segment elevation received thrombolytic therapy and were followed up for 12 months. Intravenous streptokinase was given to 315 patients and recombinant tissue-type plasminogen activator (rt-PA) to 141 patients. Reinfarction rate and risk factors for reinfarction were assessed. Management after thrombolysis was conservative; revascularization procedures were reserved for patients with symptoms refractory to medical therapy or for those with left main coronary artery stenosis. Coronary artery surgery or angioplasty was performed in only 3.7% of patients during the first 30 days after thrombolysis and in only 8.6% by 1 year. Most patients (79%) underwent coronary arteriography.
Twenty-six patients (5.7%) exhibited signs of threatened reinfarction at 1 month after thrombolytic therapy as did 43 patients (9.4%) by 1 year. Reinfarction was prevented in four of these patients by early readministration of thrombolytic therapy. Multivariate analysis of possible risk factors for reinfarction identified at the time of initial infaction showed current cigarette smoking to be the only predictive factor (reinfarction occurred in 12.5% of smokers versus 6.3% of nonsmokers, p = 0.04). A second analysis of risk factors identified 3 weeks after initial infarction, including the severity of residual stenosis at coronary arteriography and exercise test variables, again showed continued cigarette smoking to be the only factor predictive of reinfarction. Twenty percent of patients who continued to smoke developed reinfarction compared with 5.1% of those who stopped (p < 0.01).
Conservative management after thrombolysis with streptokinase or rt-PA results in a reinfarction rate of 8.6% at 1 year. Cigarette smoking predisposes patients to reinfarction; cessation of smoking reduces the risk of reinfarction. The impact of threatened reinfarction can be limited by prompt readministration of thrombolytic therapy.
☆ This study was supported by the Medical Research Council of New Zealand and the National Heart Foundation of New Zealand, Auckland.
- Received November 2, 1989.
- Revision received February 13, 1990.
- Accepted March 13, 1990.