Treatment of Coronary Risk Factors Some More Good News!
Abstract & Commentary
By Jonathan Abrams, MD Professor of Medicine, Division of Cardiology, University of New Mexico, Albuquerque Dr. Abrams serves on the speaker's bureau for Merck, Pfizer, and Parke-Davis.
Source: Setoguchi S, et al. Improvements in long-term mortality after myocardial infarction and increased use of cardiovascular drugs after discharge. J Am Coll Cardiol. 2008;51: 1247-1254.
Setoguchi and colleagues assessed the degree of utilization of guideline (Class I) protective drugs in elderly patients who survived an acute MI (AMI) and at least 30 days thereafter. The study population consisted of "community-dwelling elderly" whose drug use was interrogated using a number of databases, including Medicare claims and pharmaceutical and statewide drug assistance programs in New Jersey and Pennsylvania. Patients with AMI between January 1995 and December 2004, who filed a claim for services and had a least one filled prescription, were eligible for study analysis. Subjects had to survive for at least 30 days post AMI. A great deal of information was collected, including comorbid conditions and use of statins, beta blockers, ACE-ARB, and antiplatelet agents 30 days or more from the discharge date. Comorbidities were many and included hypertension, CAD, prior MI, heart failure, stroke, peripheral vascular disease, atrial fibrillation, and diabetes. MI characteristics, length of stay, and use of coronary interventions were tracked. Prior health care utilization and prescription use were confirmed. Kaplan-Meier curves were constructed for adjusted and unadjusted mortality, as well as adjusted time trends using a multivariate Cox proportional hazards regression model. Importantly, assessment of cardiovascular drug use, thrombolytic therapies, revascularization, and the effect of calendar year on mortality were introduced into the statistical analysis. The study cohort consisted of 29,000 patients admitted for an MI between January 1, 1995 and December 31, 2004, who had been active participants in an insurance program for at least one year before the MI and survived for at least 30 days. The final cohort consisted of 21,000 patients with a mean age of 80; 73% were women. Two-thirds had a prior diagnosis of CAD, two-thirds had heart failure, and one-third had cerebrovascular disease; almost half had diabetes and 40% had COPD. New diagnoses were confirmed over the course of the study as new diseases became evident. The use of PCI increased over time, while thrombolytic therapy for the index MI decreased. The use of statins, beta blockers, and ACE I-ARB all increased over the ten years of the study (P = < 0.01).
Overall, there were 12,000 deaths during 75,000 person years of follow-up, with one-, three-, and five-year mortality of 20%, 41%, and 57%, (approximately 20% per year) respectively. Unadjusted and adjusted data on the effects of calendar year were calculated using Cox proportional hazard regression. In unadjusted analyses, temporal change of trends in mortality were observed. After adjustment for demographics, comorbidities, and health service use over time, the analysis showed that mortality after MI improved by 3% per year between 1995-2004. "To assess whether the secular trends toward greater use of invasive cardiac procedures and/or the study medications explained the improvement in mortality after MI over time, we sequentially added these factors to the fully adjusted Cox proportional hazards regression model." When analysis of medication use was performed, the temporal trend in reduced mortality was no longer apparent, although when PCI was assessed, there was an improvement in mortality trends. Setoguchi et al suggest that the increased use of PCI over time may have "predominantly improved acute and short-term mortality, whereas increased use of preventive medications may be responsible for improvements in longer-term outcomes in the population." As the patients aged, there were increases in major comorbidities, as well as advances in the treatment of MI, resulting in older and sicker patients who survived the initial MI.
Setoguchi et al briefly reviewed other studies on the issue of longevity following MI, and found them generally concordant with the present findings. Setoguchi et al believe that their study is the first to suggest that the improved prognosis after an MI "may be attributable to the increased use of medication for secondary prevention," and to a lesser degree, use of PCI. These data should encourage clinicians to continue, and even expand, use of these proven therapies in the management of elderly patients after MI.
An accompanying editorial by Boden and Maron emphasizes the "profound decreases in CAD mortality...fueled by substantial decreases in major cardiovascular risk factors." Setoguchi et al believe that there is a "compelling rationale for formulating clinical practice guidelines" to emphasize evidence-based medications, especially in high-risk groups such as the elderly. They note that there is a "treatment-risk paradox in the elderly, meaning that there is paradoxically less aggressive evidence-based secondary prevention than in the younger lower-risk patients." Other studies have indicated that the elderly are less likely to receive appropriate therapy to ACS or STEMI in addition to being less likely to undergo revascularization." They call for physicians to utilize evidence-based prevention agents as readily and intensively in high-risk elderly patients as in younger CAD patients at lower risk.
Commentary
This elaborate analysis, while being speculative to some degree in that the data rely on a number of databases that are not linked together, is concordant with the increasingly obvious view that evidence-based medical therapy is effective in reducing death following myocardial infarction in older patients, which is similar to patients who are younger. A number of trials, including COURAGE and OAT, indicate that there is a comparable risk reduction in younger vs older patients with the use of "optimal medical therapy" combined with PCI. Medical therapy, as emphasized in the Setoguchi report, is consistent with ACC/AHA guidelines and amplifies the "polypill" concept, whereby a similar package of risk-lowering medications should be given to all patients who have established coronary artery disease, be they young or old and be they symptomatic or asymptomatic. This cocktail is also appropriate following bypass surgery and PCI, with or without a history of MI. Assessment of the multiple publications focusing on appropriate cardiovascular medicines and the multitude of scientific meetings that support the use optimal medical therapy for atherosclerosis, has helped us reach the conclusion that there truly has been a changing paradigm regarding best possible treatment of patients who have coronary disease, particularly high-risk patients who have had an MI. The components of the "package" of medications in use today may be altered over the next few years, with addition/deletion of some drugs, but it appears unlikely that the agents cited (antiplatelet therapy, angiotensin converting enzyme blockers, beta blockers, and statins) will no longer to be mandated for the treatment of vascular disease. While the Setoguchi report is not of a trial or study, but rather observational data from different data bases, the size of the cohort (20,000 patients) and the consistency of the data, with mortality improvements on a yearly basis, clearly indicate that optimal medical therapy, as used today, will be with us for a long time to come. This good news indicates a healthier balance between the use of PCI or medications alone, as well as the recognition that all patients at risk should receive the prevention cocktail, regardless of a history of revascularization.
Setoguchi and colleagues assessed the degree of utilization of guideline (Class I) protective drugs in elderly patients who survived an acute MI (AMI) and at least 30 days thereafter.You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
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