The impact of circulating total homocysteine levels on long-term cardiovascular mortality in patients with acute coronary syndromes.

BACKGROUND: To evaluate the possible independent impact of circulating total homocysteine (tHcy) levels on long-term cardiovascular mortality, in patients with either ST-segment elevation myocardial infarction (STEMI), or non-ST-segment elevation acute coronary syndromes (NSTE-ACS). METHODS: A total of 458 STEMI and 476 NSTE-ACS patients who presented consecutively, within the first 12 and 24 h of index pain respectively were studied. Each cohort was divided according to tertiles of circulating tHcy levels upon presentation. Early (30 days) and late (31 days through 5 years) cardiovascular mortality was the predefined study endpoint. RESULTS: There was no difference in the risk of 30-day cardiovascular death among the tertiles of tHcy in patients with STEMI (7.2%, 8.5% and 12.4% for the first, second and third tertiles respectively; p(trend)=0.3) or NSTE-ACS (3.1%, 3.8% and 5.7% for the first, second and third tertiles respectively; p(trend)=0.5). Patients in the upper tHcy tertile were at significantly higher unadjusted risk of late (from 31 days trough 5 years) cardiovascular death than those in the other two tertiles in STEMI (23.4%, 27.9% and 41.8% for the first, second and third tertiles respectively; p(trend) <0.001), and NSTE-ACS (24.7%, 28.1% and 45.6% for the first, second and third tertiles respectively; p(trend) <0.001) cohorts. However, after adjustment for baseline differences, there was no significant difference in the risk of late cardiovascular death among tHcy tertiles in either cohort. When circulating tHcy levels were treated as a continuous variable, they were significantly associated with late cardiovascular death (p<0.001 for both cohorts) by univariate Cox regression analysis, but not by multivariate Cox regression analysis (p=0.8, and p=1 for STEMI and NSTE-ACS cohorts, respectively). CONCLUSIONS: Based on the present data circulating tHcy levels determined upon admission do not serve as an independent predictor of long-term cardiovascular mortality in patients with either STEMI or NSTE-ACS.

The impact of hs C-reactive protein and other inflammatory biomarkers on long-term cardiovascular mortality in patients with acute coronary syndromes.

We evaluated whether high circulating levels of serum amyloid A (SAA), fibrinogen, interleukin-6 (IL-6) or leukocytes count (LC), can provide any additional predictive value over that provided by hs C-reactive protein (hs-CRP) for the incidence of 5-year cardiovascular mortality, in 458 and 476 consecutive patients with ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation acute coronary syndromes (NSTE-ACS), respectively. By 5 years the incidence of cardiovascular mortality was 37.3% and 35.5% in patients with STEMI and NSTE-ACS, respectively. Each of the study inflammatory biomarkers conferred independent to clinical risk predictors (and to cardiac troponin I) long-term prognostic information (all p<0.05), but only LC provided additional predictive value over that provided by hs-CRP, in either cohort (p<0.05). By multivariate Cox regression analysis, hs-CRP (p<0.001 for both cohorts) and LC (p=0.009 and p<0.001 for STEMI and NSTE-ACS, respectively) were the only inflammatory biomarkers independently associated with the incidence of 5-year cardiovascular mortality. According to the present results high circulating levels of LC but not of SAA, fibrinogen or IL-6 can provide additional long-term predictive value over that provided by hs-CRP in patients with acute coronary syndromes.

QT-interval dispersion in acute myocardial infarction is only shortened by thrombolysis in myocardial infarction grade 2/3 reperfusion.

BACKGROUND: Increased QT interval dispersion (QTd) has been found in patients with acute myocardial infarction (AMI). In previous studies this has been shown to decrease with thrombolysis. HYPOTHESIS: The aim of this study was to compare the effects of reperfusion by primary percutaneous transluminal coronary angioplasty (PTCA) and by thrombolysis on QTd and correlate these results with the degree of reperfusion. METHODS: We studied 60 patients with a first AMI. The study cohort included 40 consecutive patients who had received thrombolysis (streptokinase or rt-PA); 20 additional consecutive patients with successful primary PTCA, all with preselected Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow by predefined selection criteria (12 stents); and 20 controls. A 12-lead ECG for QTd calculation was recorded before thrombolysis or PTCA and immediately after the procedure. All values were corrected according to Bazett's formula (QTcd). QTd and QTcd values before and after each procedure in three groups and the respective percent changes of deltaQTd and deltaQTcd were compared separately. RESULTS: QTd and QTcd were significantly increased before thrombolysis/PTCA versus normals. An angiogram performed after thrombolysis showed adequate reperfusion (TIMI grade 2/3) in 20 patients, while in the other 20 only TIMI 0/1 reperfusion was achieved. Thrombolysis-TIMI flow 2/3 and PTCA significantly reduced QTd (from 68 +/- 10 to 35 +/- 8 ms, p < 0.001, deltaQTd = 48 +/- 11%, in the Thr-TIMI flow 2/3 group,and from 79 +/- 11 to 38 +/- 9 ms, p < 0.001, deltaQTd = 52 +/- 9%, in the PTCA group), while in the Thr-TIMI flow 0/1 group no significant changes were recorded. A percent QTd decrease > 30 s had 96% sensitivity, 85% specificity, and 93% positive and 94% negative predictive value, respectively, for TIMI 2/3 flow. CONCLUSIONS: A significant decrease in QT dispersion may provide an additional electrocardiographic index for successful (TIMI 2/3) reperfusion.