[Use of coronary angiography after acute myocardial infarction in Germany: a comparison of daily clinical practice with international guidelines. MITRA Study].

OBJECTIVES

Two third of patients with acute myocardial infarction are admitted to hospitals without cardiac catheterization facilities. Whether a postinfarction patient will undergo cardiac catheterization or not is more often decided by general physicians than by cardiologists. The purpose of this presentation is to investigate the determinants for decision making to use cardiac catheterization in patients after myocardial infarction.

METHODS

MITRA is a prospective, multicenter registry, which enrolls all consecutive patients with acute Q wave infarction admitted to 54 hospitals in Southwestern Germany. During the pilot phase 949 consecutive survivors of acute myocardial infarction were included, and inhospital outcome as well as therapeutic strategies were registered.

RESULTS

Only half of the patients underwent cardiac catheterization regardless of whether a catheterization facility was available or not. In 63% of the patients under 65 years of age coronary angiography was performed; however, every fourth patient with age above 70 years was transferred to an invasive therapeutic strategy. The percentage of male patients was twice a high in the invasive group, whereas patients with prior infarction, clinical signs of congestive heart failure, patients with moderately or severely impaired left ventricular function, and finally patients with a prehospital delay of more than 4 hours were more frequent in the conservative group. The following three parameters were calculated to be independent determinants of an invasive strategy: pathological stress ECG (OR: 2.8; CI: 1.80-4.60), patients < 70 years without stress ECG (OR: 2.18; CI: 1.5-3.18), and male gender (OR: 1.45: CI: 1.10-2.00). Independent factors of a conservative strategy were primary PTCA (OR: 0.2; CI: 0.09-0.46), prehospital delay > 4 hours (OR: 0.71; CI: 0.51-0.97), and the combination of age > 70 years and the absence of a stress ECG (OR: 0.78; CI: 0.55-1.11).

CONCLUSIONS

In Germany, patients with acute myocardial infarction are less likely to undergo cardiac catheterization compared to patients in other Western countries (e.g. , the United States). Despite recommended guidelines, invasive strategies are more frequent in low risk groups (younger patients, male gender) than in postinfarction patients at high risk (severely impaired left ventricular function, clinical signs of congestive heart failure, the elderly).