Search

Objectives: Postconditioning has been reported to reduce infarct size in ST-segment myocardial infarction (STEMI). However, recently, few other studies did not show any effect of postconditioning and suggested that it may be even harmful. We sought to assess whether postconditioning could reduce infarct size and improve myocardial reperfusion in early presenters with STEMI. Methods: 72 STEMI patients treated with primary percutaneous coronary intervention (PCI) were randomly assigned to either the postconditioning (n = 35) or the standard PCI group (control group; n = 37). Blood samples were obtained for creatine kinase (CK) and its MB isoform (CK-MB) within 36 h. The angiographic (myocardial blush grade, MBG) and electrocardiographic (ST-segment resolution, STR) data were evaluated and compared between groups. Results: The areas under the curve of CK and CK-MB release were significantly reduced in the postconditioning group compared with the control group (38,612.91 ± 25,028.42 vs. 60,547.30 ± 25,264.63 for CK and 5,498.23 ± 3,787.91 vs. 7,443.12 ± 3,561.13 for CK-MB, p < 0.0001). MBG was significantly better in the postconditioning group than in the control group (MBG 3: 82.3 vs. 47.1%, p = 0.0023). In the postconditioning group, STR >70% was more often observed (97.1 vs. 64.1%, p = 0.0007). Conclusions: In patients with STEMI, postconditioning could significantly reduce enzymatic infarct size and improve myocardial reperfusion.

Objectives: The aim of this single-center, randomized placebo-controlled trial in 70 consecutive patients (64 ± 14 years) with acute myocardial infarction was to examine the role of a new protocol of adenosine administration during primary angioplasty on immediate electrocardiographic and angiographic results, clinical outcome and 1-year follow-up. Methods: Group A (n = 35) twice received intracoronary adenosine through the guiding catheter: immediately after crossing the lesion of the infarct-related artery with guidewire and then after first balloon inflation. Group B (n = 35) received placebo. Results: Resolution of ST segment elevation was more frequently observed in the adenosine than in the placebo group (p < 0.01). Percutaneous coronary intervention (PCI) resulted in borderline better TIMI 3 flow after the procedure in the adenosine group than in the placebo group. Myocardial blush grade 3 at the end of the procedure was significantly improved in the adenosine compared to the placebo group (p < 0.05). At 1-year the composite end-point of death, recurrent myocardial infarction, heart failure and clinically driven target vessel revascularization was present in 8 patients in the adenosine group and 16 patients in placebo group (p < 0.05). Conclusions: Intracoronary adenosine improved electrocardiographic and angiographic results in patients undergoing primary PCI and seemed to be associated with more favorable clinical course.

Background: There are no reliable non-invasive markers of restenosis after percutaneous transluminal coronary angioplasty (PTCA). The aim of our study was to measure changes in QT interval dispersion after PTCA and to determine whether restenosis subsequently affects QT interval dispersion. Methods and Results: Fifty-six consecutive patients – 41 men and 15 women (mean age: 56.2 ±8.3 years) – with isolated stenosis of the left anterior descending artery who underwent successful PTCA were studied. A symptom-limited treadmill exercise test was performed within 7 days after PTCA and then again before repeated angiography. Repeated coronary angiography revealed restenosis in 15 patients (26.8%) and no signs of significant stenosis in 41 patients (73.2%). QT interval dispersion in the group of patients with restenosis measured before exercise increased from baseline 34 ± 7 to 49 ± 15 ms after 6 months (p < 0.01) and QT interval dispersion measured immediately after exercise increased from baseline 38 ± 4 to 68 ± 21 ms after 6 months (p < 0.001). In contrast, patients without restenosis showed no significant changes in QT interval dispersion measured before (baseline: 34 ± 9 ms; after 6 months 33 ± 12 ms; p = NS) and immediately after exercise (baseline: 34 ± 12 ms; after 6 months: 33 ± 10; p = NS). When QT interval dispersion ≧60 ms (measured 6 months after PTCA procedure) was considered as a potential marker of restenosis, this indicator had very high sensitivity and specificity when measured immediately after exercise (80 and 95% respectively). Conclusions: QT interval dispersion significantly increases in the group of patients with documented restenosis and may be a simple, non-invasive marker of restenosis. However, further studies are needed to confirm this observation.