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Treatment & Statistics: Mortality after Myocardial Infarction
Some therapies and statistics on mortality rate after myocardial infarction: Beta-blockers a) Study, in which 69,336 patients have received different beta-adrenergic blockers, show that mortality rates of the 2 selective agents, metoprolol and atenolol, were identical (13.5% and 13.4% in 2-year mortality, respectivelly), and with propanolol had a slightly increased mortality (15.9% in 2-year mortality) (1) b) The Carvedilol Post-Infarct Survival Control in LV Dysfunction (CAPRICORN) trial, enrolling 1959 patients with left ventricular dysfunction following acute MI, in a mean follow-up of 15 months, show the following chances of benefit in patients taking beta-blockers over placebo after myocardial infarction (2, 3): - Total mortality in 15 months: 11.9% (beta-blockers) x 15.3% (placebo) - Absolute risk reduction in mortality = 3.4% - NNT to prevent one death in the whole study = 28 - NNT to prevent one death for one year of treatment at CAPRICORN trial study: 43 * NNT (Number of Patients Needed to Treat) at the CAPRICORN trial study means that: - 43 patients are needed to treat with beta-blockers to prevent one death in one year of treatment - 28 patients are needed to treat with beta-blockers to prevent one death during the follow-up of 15 months. Statins Study made in 4159 patients with prior myocardial infarction with average cholesterol levels randomized to therapy with pravastatin or placebo and followed for an average of 5 years show no statistically significant effect on all cause mortality (9.4% vs 8.7%). The reduction in-non fatal myocardial infarction incidence was 11.1% to 8.7% (absolute risk reduction of 2.4%) , representing in practice the need to treat 42 patients (NNT) for five years to avoid one non-fatal MI (4). Aspirin a) The ISIS-2 trial of short term antiplatelet therapy, in which 17187 patients with suspected acute myocardial infarction were randomized, half to active aspirin and half to placebo showed a reduction in five week all cause mortality of 9.4% (811/8597) for aspirin vs 12% (1030/8600) for placebo, representing an absolute risk reduction in mortality of 2.6% and a NNT = 38. (5). b) Other large long term trials of aspirin after myocardial infarction show no effect on mortality. On contrary they report an increase of sudden death in post-infarction trials (6, 7, 8, 9) Digitalis a) The Sprint Study Group (10) found in one year the very low mortality rate of 2% in patients recovering from acute myocardial infarction treated with low dose digoxin (1 of 41 patients). b) A Brazilian study (11), with a follow-up of 28 years, found a mortality rate of 41% (1.4% per year) in 156 patients recovering from acute myocardial infarction treated with digitalis (digoxin, digitoxin, acetyldigoxin, beta-methyldigoxin or lanatoside-C). References:
1. Gottlieb SS, McCarter RJ. Comparative effects of three beta
blockers (atenolol, metoprolol, and propanolol) on survival after
acute myocardial infarction, Am J Cardiol 2001 Apr 1;87(7):823-6
2. Otterstad JE, Ford I. The effect of carvedilol in patients with
impaired left ventricular systolic function following an acute myocardial infarction. How do the treatment effects on total mortality and recurrent myocardial infarction in CAPRICORN compare with previous beta-blocker trials? Eur J Heart Fail. 2002 Aug;4(4):501-6. 3. Borrello F, Beahan M, Klein L. Reappraisal of beta-blocker therapy in the acute and chronic post-myocardial infarction period. Rev Cardiovasc Med. 2003;4 Suppl 3:S13-24. 4. Sacks F, Pfeffer M, Moye L, et al, The effect of pravastatin on coronary events after myocardial infarction in patients with average cholesterol levels, New England Journal of Medicine, 335:1001-9. October 3, 1996 5. ISIS-2 Collaborative Group. Randomised trial of intravenous streptokinase, oral aspirin, both, or neither among 17,187 cases of suspected acute myocardial infarction. Lancet 1988;ii:349-360 6. The Persantine-Aspirin Reinfarction Study (PARIS) Research Group. Persantine and aspirin in coronary disease. Circulation 1980;62:449-462 7. The Aspirin Myocardial Infarction Study Research Group. The aspirin myocardial infarction study: final results. Circulation 1980;62:V79-V84 8. Klimit CR, Knatterud GL et al. Persantine-aspirin reinfarction study. Part II. Secondary coronary prevention with persantine and aspirin. J Am Coll Cardiol 1986;7:251-269 9. John G F Cleland. For Debate, Preventing atheorsclerotic events with aspirin, BMJ, 324:103-105, Jan 12, 2002 10. Leor J, Goldbourt U et al. Digoxin and increased mortality among patients recovering from acute myocardial infarction: importance of digoxin dose, Cardiovasc Drugs Ther 1995 Oct;9(5):723-9 11. Quintiliano H de Mesquita, Claudio A S Baptista. Cardiotonic: Insuperable in preservation of myocardial stability as preventive of acute coronary syndromes and responsible for the prolonged survival. Ars Cvrandi, May 2002;35:3 (See at http://www.infarctcombat.org/heartnews-16.html )
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