Impacts of glycoprotein IIb/IIIa inhibition on QT dispersion after successful percutaneous coronary intervention.

Coronary ischemia augments inhomogeneity in ventricular repolarization. Decrease in the QT dispersion (QTd) following restoration of coronary blood flow to the ischemic myocardium by successful percutaneous coronary intervention (PCI) is an expected outcome. The purpose of the study was to seek whether glycoprotein IIb/IIIa (GP IIb/IIIa) inhibition has additional beneficial effects on QT dispersion after angiographically successful PCI. The study involved 111 consecutive patients scheduled for elective coronary balloon angioplasty with or without stent implantation. Sixty patients (mean age 58 +/-9) were randomized to receive standard therapy including preprocedural aspirin, ticlopidine, and IV heparin, and 51 patients (mean age 54 +/-10) were randomized to receive additional IV tirofiban infusion before the lesion was crossed with the guidewire. Standard 12-lead simultaneous ECG recordings for the measurement of QTd and corrected QTd (QTcd) (calculated by using Bazett's formula) were obtained before and immediately after the procedure, and at the 6th, and 24th hours. Blood samples for detection of postprocedural myocardial damage (CK-MB and cTn-I) were taken before and immediately after the procedure, at the 6th, 12th, and 24th hours. In total, 128 stenoses were treated with PCI. Seventy of these lesions were in the standard therapy group and 58 in the tirofiban group. QTd and QTcd were not statistically different between the 2 groups before and immediately after the procedure and at the 6th hours, but at the 24th hour QTd and QTcd were significantly longer in the standard therapy group (p=0.047 and p=0.001, respectively). Postprocedural troponin-I elevation (B=0.692, p=0.037), maximum inflation pressure (B=0.182, p=0.001), and previous myocardial infarction (MI) (B=0.885, p=0.004) were defined as the predictors of the final QT dispersion at the 24th hour. QT dispersion significantly decreased after successful percutaneous coronary intervention. GP IIb/IIIa inhibition therapy was not superior by means of recovery of increased QT dispersion during the early hours of the intervention, but it prevented minor myocardial necrosis and provided more long-lasting recovery in QT dispersion as compared with heparin therapy. This impact of GP IIb/IIIa receptor inhibition on QTd may be a possible mechanism by which these drugs reduce cardiovascular events after PCI.

Cardiac troponin I increase after successful percutaneous coronary angioplasty: predictors and long-term prognostic value.

After successful percutaneous coronary interventions (PCI), elevations of cardiac enzymes are not rare, but it is still not clear whether those elevations are associated with adverse late outcome. The purpose of the study was to investigate the relation between cardiac troponin I (cTn-I) increase after successful percutaneous intervention and late outcome. The study consisted of 100 consecutive patients (mean age 56 +/-9.8, 84% male) who had successful elective coronary balloon angioplasty with or without stent implantation. Patients with stable angina (n=54) and unstable angina (n=46) were included in the study. Blood samples for measurement of cTn-I were taken before and immediately after the procedure, and every 6 hours for the first 24 hours. Patients with preprocedural cTn-I elevation were excluded from the study. Postprocedural cTn-I elevation was detected in 34 patients (34%, troponin (+) group) and cTn-I levels were normal in 66 patients (66%, troponin (-) group). Logistic regression analysis showed that intervention in patients with unstable angina, stent implantation following balloon dilation, and maximal inflation pressure were the predictors of cTn-I elevation (p=0.035, p=0.038, and p=0.014, respectively). During the prospective follow-up period for 21 +/-7.5 months, the incidence of major cardiac events including recurrent angina, acute myocardial infarction, death, and revascularization were not different in patients with and without cTn-I elevation. Overall, major cardiac events occurred in 9 patients (26%) in the troponin (+) group and in 13 patients (20%) in the troponin (-) group. Kaplan-Meier survival analysis showed that cTn-I elevation was not an important correlate of overall cardiac events (log-rank: 1.66, p=0.19). The authors conclude that postprocedural cTn-I elevation is related to unstable angina, stent implantation following predilation, and inflation pressure, and there is no association with minor myocardial injury occurring after successful percutaneous coronary intervention and late adverse cardiac events.

Adrenal adenoma presenting with ventricular fibrillation.

We report the case of a 58-year-old man who presented with ventricular fibrillation. The serum potassium level was 1.8 mEq/L after successful cardioversion. Coronary angiography showed a normal heart with no structural defects, but 12-lead electrocardiography showed indications of left ventricular hypertrophy, which was confirmed by echocardiography. Laboratory examinations showed a suppressed renin level and an elevated serum aldosterone level. Computed tomography then revealed a right adrenal mass. The patient was treated with surgical resection of the adenoma. This case emphasizes the importance of meticulous search for secondary causes of hypertension, before the occurrence of serious complications.

Correlations between cardiac troponin I, cardiac troponin T, and creatine phosphokinase MB elevation following successful percutaneous coronary intervention and prognostic value of each marker.

AIMS: The aim of this prospective cohort study was to examine correlation between the postprocedural absolute rise of cardiac troponin (cTn-I), cardiac troponin T (cTn-T), and creatine phosphokinase MB (CK-MB), and predictive value of each marker for the long-term cardiac events following successful percutaneous coronary interventions. METHODS: The study consisted of 111 consecutive patients who had angiographically successful coronary balloon angioplasty with or without stent implantation. cTn-I, cTn-T, and CK-MB were measured before, immediately after the procedure, and every 6 hours for the first 24 hours. Patients were followed-up for major adverse cardiac events including acute myocardial infarction, death, recurrent angina, and revascularization for a period of 21+/-8.2 months. RESULTS: Total 45 patients (40%) had postprocedural cTn-I elevation, 27 patients (24%) cTn-T elevation, and 17 patients (15%) CK-MB elevation. There were strong correlations between the absolute values of the postprocedural maximal cTn-I and cTn-T, cTn-I and CK-MB, cTn-T and CK-MB (r: 0.64, r: 0.64, and r: 0.70 respectively, p<0.0001 for all correlations). There was also a significant concordance between the post-procedural positivity (higher than upper limit of normal) of cTn-I and cTn-T (kappa: 0.59), but CK-MB did not show significant concordances with c-Tn-T (kappa: 0.42), and cTn-I (kappa: 0.38). Long-term major cardiac events were observed in 29 patients (27%). Higher than 4-fold increase in cTn-I (log rank: 5.0, p: 0.02), and cTn-T (log rank: 10.7, p<0.001), and 2- to 4-fold in CK-MB (log rank: 17.9, p<0.0001) showed marked decremental effects on the event free survival. CONCLUSION: Although the cTn-I is found to be relatively more sensitive cardiac marker, cTn-T can be used as an alternative assay with significant correlation, concordance, and prospective value. Both troponins have predictive value for long-term event free survival; particularly 4-fold increase is associated with worse event free survival.

Asystole associated with cluster headache.

A 43-year-old man with asystole and syncope occurring during cluster headache attacks is reported. The asystole and syncope attacks disappeared completely following prophylactic therapy with methysergide maleate. To the authors' knowledge, the present case is unique in associating asystole with cluster headache attacks and may be due to hyperactivity of the parasympathetic system.

Effects of direct stent implantation and conventional stent implantation on minor myocardial injury.

Direct coronary stenting without balloon predilation has the potential benefits of a reduced risk of extended dissections, reduced fluoroscopy exposure, reduced procedural time, and potential cost savings. The purpose of the study was to compare the effects of angiographically successful direct stent implantation and conventional stent implantation (stent implantation following predilation) on minor myocardial injury characterized by cardiac troponin I (cTn-I), and cardiac troponin T (cTn-T) elevation. The authors prospectively studied 42 patients who had successful direct stent implantation, and 49 patients who had successful conventional stent implantation. Blood samples for measurement of cTn-I and cTn-T were taken before, and immediately after the procedure, and every 6 hours for the first 24 hours. cTn-T elevation was observed in 6 patients (14.3%) in the direct stent implantation group, and in 16 patients (32.6%) in the conventional stent implantation group (p: 0.03). Similarly cTn-I elevation was more frequent in the conventional stent implantation group (20 patients, 40.8%) than direct stent implantation group (7 patients, 16.7%, p: 0.02). Stent implantation following predilation is more frequently associated with postprocedural minor myocardial injury than direct stent implantation.

Left main coronary artery aneurysm associated with extensive coronary arterial calcification: case report and review.

We present a 68-year-old male with left main coronary artery aneurysm and extensive coronary calcification involving the entire coronary arterial tree detected by coronary angiography and electron beam computerized tomography. With this article we also discussed the relationships between the pathogenesis of coronary atherosclerosis, coronary calcification, and coronary aneurysm formation.

Long-term follow-up after angiographically successful coronary stenting: direct stent versus conventional stent implantation.

The purpose of the study was to compare the impacts of angiographically successful direct stent implantation and conventional stent implantation (stent implantation following predilatation) on long-term major cardiac events. The authors prospectively studied 40 patients who had successful direct stent implantation and 46 patients who had successful conventional stent implantation. The end-point of the study was defined as the occurrence of a major cardiac event, including recurrent angina, acute myocardial infarction, death, and target vessel revascularization. The demographic and clinical characteristics of the study groups were similar, except the indication of percutaneous angioplasty, which was more frequently unstable angina in the conventional stent group (63% vs 38%, P: 0.03). Procedural minor complications were more frequent in conventional stent implantation, and there was also a positive correlation between the conventional stent implantation and procedural minor complications (r = 0.231, P: 0.03), and postprocedural troponin elevation (r = 0.221, P: 0.04). The incidences of major cardiac events including recurrent angina, acute myocardial infarction, death, death or myocardial infarction, and target vessel revascularization were not different between the study groups during the long-term follow-up period (21 +/- 7.1 months for direct stent group and 20 +/- 7.5 months for conventional stent group). Overall end-points occurred in 9 patients (22%) in the direct stent group and in 9 patients (19%) in the conventional stent group. Kaplan-Meier survival analysis showed that there was no difference in event-free survival between the patients treated with direct stent implantation and conventional stent implantation (log-rank: 1.52, P = 0.21). Two-vessel intervention and hypertension were found to be related with long-term major cardiac events (r = 0.214, P: 0.048, r = 0.206, P: 0.04, respectively). In addition to the procedural advantages, direct stent implantation may also provide comparable results with conventional stent implantation concerning the late cardiac events following successful percutaneous coronary angioplasty.

Effects of glycoprotein IIb/IIIa receptor inhibition with tirofiban on minor myocardial damage in angiographically successful percutaneous coronary angioplasty.

AIM: The aim of the study was to evaluate the effects of glycoprotein (GP) IIb/IIIa inhibition on minor myocardial injury characterized by cardiac troponin I (cTn-I) and cardiac troponin T (cTn-T) elevation after elective successful percutaneous coronary intervention (PCI). METHODS: The study consisted of 119 consecutive patients scheduled for elective coronary balloon angioplasty with or without stent implantation. Sixty-three patients (mean age 58 +/- 9.4 years) were randomized to receive standard therapy, including preprocedural aspirin, ticlopidine and intravenous heparin, and 56 patients (mean age 55 +/- 9.6 years) were randomized to additionally receive intravenous tirofiban infusion. cTn-I, cTn-T and CK-MB were measured before and immediately after the procedure, and every 6 h for the first 24 h. A total of 128 stenoses were treated with PCI. Seventy of these lesions were in the standard therapy group and 58 in the tirofiban group. RESULTS: The frequency of postprocedural abnormal cTn-I levels was significantly higher in the standard therapy group than that in the tirofiban group (37 vs. 16%; p = 0.017). Postprocedural cTn-T elevation occurred in 23% of patients in the standard therapy group and in 8% of patients in the tirofiban group (p = 0.037). The frequencies of CK-MB elevation higher than the upper limit of normal (ULN), and higher than 2 times the ULN were not significantly different between the standard therapy and tirofiban groups (12 vs. 4%, and 7 vs. 2%, respectively). CONCLUSIONS: GP IIb/IIIa inhibition may reduce the incidence of minor myocardial injury, which may also be a possible mechanism in reducing long-term cardiac events after PCI.

New-onset conduction defects and their relationship with in-hospital major cardiac events in unstable angina pectoris.

BACKGROUND: The aim of this prospective cohort study was to describe the incidence and the risk factors for the development of intraventricular conduction defects and the relationship of these defects with in-hospital major cardiac events (MACE) in unstable angina pectoris. METHODS: Two-hundred-and-seventy consecutive patients presenting with Braunwald class IIIB angina without a conduction defect at admission were included in the study and followed up during the in-hospital period. RESULTS: Fifty-one patients who developed non-ST-elevation myocardial infarction during the first day were excluded from the study. Of the remaining 219 patients, 40 (18%) had a new permanent conduction defect (group 1) and 179 (82%) did not have a conduction defect (group 2) during the in-hospital period. The patients in group 1 were significantly older (mean age of 63.5 +/- 11 years compared with 59 +/- 10 years, P = 0.01) and a history of previous coronary artery bypass grafting (CABG) was more frequent in this group (12.5% compared with 1.6%, P = 0.004). By logistic regression analysis, age (P = 0.01, odds ratio (OR) = 1.473, 95% confidence interval (CI) = 1.108-2.612) and previous CABG (P = 0.005, OR = 3.995, 95% CI = 1.811-7.383) were also found to be risk factors for the development of a conduction defect. In-hospital total MACE, death and heart failure were more frequently observed in group 1 (P = 0.005, P = 0.02, P = 0.001, respectively). The incidences of recurrent refractory angina, acute myocardial infarction and urgent revascularization were not different between the groups. ST-segment depression at admission (P = 0.009, OR = 1.654, 95% CI = 1.228-2.675) and a new-onset conduction defect (P = 0.02, OR = 1.625, 95% CI = 1.244-2.754) were found to be predictors of the development of in-hospital MACE. CONCLUSIONS: In unstable angina pectoris, patients with a new-onset conduction defect are relatively older and have more frequently undergone previous CABG. Because in-hospital MACE, death and heart failure are more common in patients with a new conduction defect, they should be considered as high risk and treated more aggressively.

Effects of enoxaparin and nadroparin on major cardiac events in high-risk unstable angina treated with a glycoprotein IIb/IIIa inhibitor.

Clinical trials have reported the beneficial effects of platelet glycoprotein (GP) IIb/IIIa receptor antagonists and low-molecular-weight heparins (LMWH) on major cardiac events (MACE) in patients presenting with unstable angina or non-ST elevation myocardial infarction. A number of studies have documented the significant superiority of low-molecular-weight heparins, especially enoxaparin, over unfractionated heparin in the treatment of acute coronary syndromes. The purpose of this study was to compare the effects of two different LMWHs, enoxaparin and nadroparin, accompanied by platelet GP IIb/IIIa inhibition on MACE in high-risk unstable angina. The study was designed as an open-label and observational study. Sixty-eight patients presenting with unstable angina associated with high-risk criteria were randomly assigned to treatment with enoxaparin plus tirofiban (36 patients, mean age 57 +/- 11) or nadroparin plus tirofiban (32 patients, mean age: 58 +/- 8). In-hospital MACE including acute myocardial infarction (AMI), recurrent refractory angina, death, stroke, and urgent revascularization were compared between the study groups. Patient characteristics and durations of LMWH and tirofiban treatments were not different between the study groups. Coronary artery risk factors, except family history (which was observed more frequently in the enoxaparin group, P = 0.02), were also similar. MACE between the enoxaparin and nadroparin groups including AMI (5.5%, 6%), recurrent refractory angina (19%, 12%), death (0%, 3%), stroke (was not observed in either group), urgent revascularization (14%, 12%) and total MACE (19%, 15%) were not different. Enoxaparin and nadroparin, accompanied by GP IIb/IIIa inhibitor therapy, have similar effects on the development of major cardiac events in patients presenting with unstable angina and high-risk characteristics.

Left circumflex coronary artery bridging.

Myocardial bridging most frequently occurs on the left anterior descending coronary artery and may cause ischemia and related complications. Right coronary artery myocardial bridges (MB) are rare. We report a patient with an unusual coronary bridge, a left circumflex coronary artery bridge, who presented with exercise-induced angina pectoris that was relieved with medical therapy.