Primary percutaneous coronary interventions in acute myocardial infarction in diabetic versus non-diabetic patients. In-hospital and long-term results.

BACKGROUND: It has been well established that in the pre-thrombolytic era diabetic patients had poorer clinical outcome after acute myocardial infarction (AMI) compared to non-diabetic patients. Less is known about the impact of diabetes on early and late clinical outcomes in patients with AMI undergoing primary percutaneous coronary interventions (PCI). AIM: To compare the in-hospital and long-term clinical outcomes of AMI patients with and without diabetes.
METHODS: Seven hundred seventy-four patients who underwent primary PCI for AMI in our institution between 1997 and 2001 were included in the study. We compared the angiographic and clinical outcomes of 633 (81.8%) non-diabetic (aged 55.9+/-10.6 years; 82.6% male) and 141 (18.2%) diabetic (aged 56.8+/-11.7 years; 63.1% male) patients.
RESULTS: Diabetic patients had a higher incidence of hypertension, hyperlipidemia, and unstable hemodynamic status compared to non-diabetic patients (p=0.001, 0.003, 0.001, respectively). Smoking and male gender rates were significantly more frequent in non-diabetic patients (p=0.001, 0.001, respectively). Angiographic success and prominent clinical improvement were achieved in 96.4% and 90.7% of diabetics vs 96.7% and 95.1% of non-diabetics (p=NS and 0.04, respectively). Diabetic patients had a higher incidence of in-hospital deaths and overall events (p=0.028). At one-month follow-up, diabetic patients required more target vessel revascularisation (5.6% vs 1.6%; p=0.006), which accounted for the majority of major cardiac events at one month (20.6% vs 7.4%; p=0.003). At a mean follow-up of 7.2+/-2.7 months, 92.9% of non-diabetic and 88% of diabetic patients were still alive (p=0.05). Overall survival without any major cardiac event (death, new MI or target vessel revascularisation) at 7.2+/-2.7 month follow-up was 75.8% for non-diabetics and 58.1% for diabetic patients (p<0.01). In the multivariate analysis age, diabetes, shock, hemodynamic instability and female gender were the most important predictors for the development of early and late major cardiovascular events.
CONCLUSIONS: Primary PCI in acute MI is effective in restoring TIMI 3 coronary flow both in diabetic and non-diabetic patients. This procedure may reduce mortality in both groups, particularly in diabetic patients in whom this benefit is more prominent compared to thrombolytic therapy. Nevertheless, early and long-term event rates are significantly higher in diabetics than in non-diabetic patients.