Clinical characteristics and outcome of diabetic patients with acute myocardial infarction. Data from the BLITZ-1 study.

BACKGROUND: The determinants of a worse outcome in diabetic patients after an acute myocardial infarction (AMI) are controversial. They include delayed hospital admission, worse clinical presentation and lesser efficacy of accepted therapeutic interventions. Therefore, to improve our knowledge, we aimed to describe the clinical characteristics, treatment options and short-term outcomes of diabetic patients in a survey of consecutive AMI subjects admitted to the Italian coronary care unit (CCU) network in the current era of reperfusion.
METHODS: The BLITZ study prospectively enrolled patients with AMI, within 48 hours of symptom onset, admitted to 296 out of the 341 existing Italian CCUs from October 15 to 29, 2001. Diabetic status was recorded by collecting clinical history. In-hospital and post-discharge management and outcomes were collected up to 30 days from admission.
RESULTS: Overall, 434 of 1959 enrolled patients (22%) had a clinical diagnosis of diabetes. Diabetic patients were older, more frequently women, had a worse coronary risk profile, and an unfavorable clinical presentation compared to non-diabetics. Among 1275 patients with ST-elevation AMI, diabetics (20%) received a similar proportion of any reperfusion therapy (61 vs 66%, p = 0.10), but significantly less primary percutaneous coronary angioplasty (9 vs 16%, p = 0.003). Diabetic patients were treated less often with oral beta-blockers than non-diabetics both during hospitalization (56 vs 64%, p = 0.003) and at discharge (54 vs 61%, p = 0.01). In contrast, in-hospital use of angiotensin-converting enzyme inhibitors (76 vs 67%, p = 0.0003), digitalis (10 vs 5%, p = 0.0005), and diuretics (54 vs 36%, p < 0.0001) was more frequent among diabetics. During their index admission, subjects with diabetes had higher in-hospital mortality (11 vs 6%, p = 0.0004), as well as higher rates of reinfarction (6 vs 2%, p = 0.0003), new congestive heart failure (28 vs 14%, p < 0.0001), cardiogenic shock (10 vs 5%, p = 0.0005) or recurrent angina (22 vs 16%, p = 0.0034). A similar pattern was observed at 30-day follow-up. At multivariate analysis, diabetic status was not confirmed to be an independent predictor of 30-day mortality.
CONCLUSIONS: Although diabetic patients with AMI admitted to the Italian CCU network have a higher in-hospital and 30-day morbidity and mortality rates compared to non-diabetics, a clinical diagnosis of diabetes has no independent predictive value on short-term outcome.