Relationship between the QTc interval at hospital admission and the severity of the underlying ischaemia in low and intermediate risk people studied for acute chest pain.

BACKGROUND: The corrected QT interval (QTc) is prolonged in the setting of acute coronary artery disease. However, very little data are available concerning the relationship between the QTc obtained soon after an episode of acute chest pain (ACHP) and the magnitude and severity of the myocardial ischaemia objectified in subsequent stress tests (STS). METHODS: This was a prospective and observational study in which we investigated the relationship between the QTc determined on the hospital admission electrocardiogram (AQTc) using Bazett's formula and the results of the STS performed subsequently in 206 patients consecutively admitted to the Emergency Department for ACHP without persistent ST-elevation. RESULTS: The mean AQTc was 456+/-60 ms. There were 88 (42%) individuals with a moderately or severely abnormal STS. The AQTc was longer in the patients with a moderately or severely abnormal STS: 490+/-52 versus 430+/-56 (p<0.001) and was correlated with the probability of the patient having a moderately or severely abnormal STS (c=0.84; p<0.001). The best cut-off point was 450 ms (sensitivity, specificity and negative predictive value: 81, 77 and 84 %). Patients with AQTc>or=450 had a higher frequency of moderately or severely abnormal STS (73 versus 16%; OR: 2.9; 95% CI: 2.1-4.1; p<0.001). After adjusting for age, sex, cardiac risk factors, cardiac history, QRS duration, ST-depression, troponin I release and pre-STS medical treatment, AQTc>or=450 remained as an independent predictor (OR: 12; 95% CI: 6-24; p<0.001). CONCLUSIONS: In patients studied for ACHP, the QTc on the hospital admission electrocardiogram correlates with the underlying myocardial ischaemia. AQTc>or=450 ms selects a group of people at risk of presenting a moderately or severely abnormal STS, regardless of ST abnormalities and troponin release.

Short- and long-term prognostic value of the corrected QT interval in the non-ST-elevation acute coronary syndrome.

BACKGROUND AND PURPOSE: Myocardial ischemia prolongs the QTc interval. Very little data exists about its prognostic implications in the non-ST-elevation acute coronary syndromes (NST-ACS). METHODS: This is and observational and prospective study in which we evaluated the prognostic implications of the QTc obtained at admission (AQTc) in the short- and long-term of the NST-ACS. The median of the follow-up was 17 months. RESULTS: AQTc correlated adequately with the incidence of adverse events in the short- and long-term (P < .001), with the best cut-off point in 450 milliseconds. Patients with AQTc > or =450 presented higher frequency of in-hospital death: 8.8% vs 1.2%; P = .001, and MACE (death, recurrent ischemia, or urgent coronary revascularization): 72% vs 25%; P < .001. In a Cox regression analysis, we found 3 independent predictors of cardiovascular death after discharge: AQTc > or =450 (14.7% vs 2.1%; P < .0001), age >65 years and left ventricular ejection fraction <40%. Coronary revascularization reduced the risk of posthospitalary cardiovascular death in AQTc > or =450 milliseconds (5% vs 24%; P < .0001) but had no significant effect in AQTc<450 milliseconds. CONCLUSION: These findings provide a new evidence supporting the prognostic value of the AQTc in predicting unfavorable events in the short- and long-term of the NST-ACS.

[Recurrent coronary thrombosis, factor V Leiden, primary antiphospholipid syndrome and HIV]. / Trombosis coronaria recurrente, síndrome antifosfolipídico primario, factor V Leiden y virus de la inmunodeficiencia humana.

We describe a 54-year-old man who was HIV-positive, admitted for cardiogenic shock complications inferior myocardial infarction. He was treated with primary percutaneous transluminal angioplasty (PCTA) and stent deployment in mid right coronary artery. After a few days thrombotic occlusion of the stent occurred, and the problem recurred during implantation of a new stent in the course of a second PTCA. We detected coinheritance of factor V Leiden, primary antiphospholipid syndrome and antithrombin deficiency. We discuss the role of these coagulation disorders in acute myocardial infarction as well as the treatment and course of the coronary syndrome in this context.