Should angiotensin-converting enzyme-inhibitors be used to improve outcome in patients with coronary artery disease and 'preserved' left ventricular function?

Heart failure and non-ST-segment elevation myocardial infarction: a review for a widespread situation

Up to 15% of patients with NSTEMI present at admission with heart failure. Scientific evidence for its management is limited but much progress has been made during the last years. Our purpose was to review the last data concerning heart failure in NSTEMI and perform an update on the subject, with the following findings as main highlights. As Killip classes III and IV, Killip class II onset in the context of NSTEMI has also proven bad prognosis significance. Beta-blocker therapy has proven benefit to patients with Killip class II in observational studies and small trials. Angiotensin-converting enzyme inhibitor therapy shows stronger evidence of benefit in patients with heart failure than in patients without it. Eplerenone is indicated for patients with left ventricular dysfunction and heart failure or diabetes mellitus. Implantable cardioverter defibrillators improve survival in patients with severe ventricular dysfunction after a myocardial infarction. Cardiac resynchronization therapy indications must be carefully assessed due to the high rate of implants that do not fulfill guidelines indications. In conclusion, heart failure during a NSTEMI is a common and meaningful situation which warrants careful management and further investigation to reach stronger evidence for clinical recommendations.

Statistics-based research--a pig in a poke?

Much of medical research involves large-scale randomized controlled trials designed to detect small differences in outcome between the study groups. This approach is believed to produce reliable evidence on which the management of patients is based. But can we be sure that the demonstration of a small, albeit statistically significant, difference is sufficient to infer the presence of a causal relationship between the drug and the outcome? A study is claimed to have internal validity when other explanations for the observed difference - namely, inequalities between the groups, bias in the assessment of the outcome and chance - have been excluded. Despite the various processes that are put into place - including, for example, randomization, allocation concealment, double-blinding and intention-to-treat analysis - it remains doubtful whether the groups are equal in terms of all factors relevant to the outcome and whether bias has been excluded. As for the exclusion of chance, not only may inappropriate statistical tests be used, but also frequentist statistics has been subjected to serious criticisms in recent years that further bring internal validity into question. But the problems do not end with the flaws in internal validity. The philosophical basis of large-scale randomized controlled trials and epidemiological studies is unsound. When examined closely, many obstacles emerge that threaten the inference from a small, statistically significant difference to the presence of a causal relationship between the drug and the outcome. Given the influence of statistics-based research on the practice of medicine, it is of the utmost importance that the flaws in this methodology are brought to the fore.

Predictors of heart failure in patients with stable coronary artery disease: a PEACE study

BACKGROUND

Heart failure (HF) is a disease commonly associated with coronary artery disease. Most risk models for HF development have focused on patients with acute myocardial infarction. The Prevention of Events with Angiotensin-Converting Enzyme Inhibition population enabled the development of a risk model to predict HF in patients with stable coronary artery disease and preserved ejection fraction.

METHODS AND RESULTS

In the 8290, Prevention of Events with Angiotensin-Converting Enzyme Inhibition patients without preexisting HF, new-onset HF hospitalizations, and fatal HF were assessed over a median follow-up of 4.8 years. Covariates were evaluated and maintained in the Cox regression multivariable model using backward selection if P<0.05. A risk score was developed and converted to an integer-based scoring system. Among the Prevention of Events with Angiotensin-Converting Enzyme Inhibition population (age, 64+/-8; female, 18%; prior myocardial infarction, 55%), there were 268 cases of fatal and nonfatal HF. Twelve characteristics were associated with increased risk of HF along with several baseline medications, including older age, history of hypertension, and diabetes. Randomization to trandolapril independently reduced the risk of HF. There was no interaction between trandolapril treatment and other risk factors for HF. The risk score (range, 0 to 21) demonstrated excellent discriminatory power (c-statistic 0.80). Risk of HF ranged from 1.75% in patients with a risk score of 0% to 33% in patients with risk score >or=16.

CONCLUSIONS

Among patients with stable coronary artery disease and preserved ejection fraction, traditional and newer factors were independently associated with increased risk of HF. Trandolopril decreased the risk of HF in these patients with preserved ejection fraction.