Frequency, risk factors, and effect on long-term survival of increased troponin I following uncomplicated elective percutaneous coronary intervention.

BACKGROUND: The frequency, risk factors for, and effect on long-term survival of increased troponin I (cTnI) following elective, uncomplicated percutaneous coronary intervention (PCI) remains uncertain. METHODS: We studied 907 patients undergoing elective PCI without recognized PCI complications and with at least 1 measurement of cTnI 12 or more h following the procedure. Patients with pre-PCI cTnI above 0.1 ng/ml or with myocardial infarction within the previous 48 h were excluded. RESULTS: Maximal cTnI (TrMX) following PCI averaged 0.8 ng/ml, exceeded the upper normal of 0.1 ng/ml in 65.2% of patients and was 1.5 ng/ml or above in 13.7%. Of several demographic and procedural variables examined, the only significant predictor of TrMX was the number of stents deployed. (p < 0.0023 95% confidence interval [CI]: 0.10-0.46). Significant univariate predictors of survival (Kaplan-Meier) were older age (p < 0.0001), diabetes (p = 0.02), peripheral vascular disease (p < 0.0001), obstructive lung disease (p < 0.0001), congestive failure (p < 0.0001), renal impairment (p < 0.0001), and TrMX of 3.62 ng/ml or above (p = 0.0451). Independent predictors (Cox) were older age (p < 0.0001), obstructive lung disease (p < 0.0001), congestive failure (p < 0.0001), and TrMX (p = 0.0272). CONCLUSIONS: Elevation of cTnI occurs in most patients undergoing elective, uncomplicated PCI. Deployment of multiple stents is associated with higher values of cTnI. Long-term survival is primarily influenced by age and pre-PCI comorbidities, however patients with the highest values of cTnI after PCI are also at increased risk of reduced survival. Significant independent predictors of reduced survival were older age, obstructive pulmonary disease, congestive failure (p < 0.0001 for each), and maximal post-PCI cTnI (p = 0.0272).

Normalization of abnormal T-waves during stress testing does not identify patients with reversible perfusion defects.

OBJECTIVE: To determine if T-wave normalization during exercise or dobutamine stress testing identified patients with myocardial ischemia as indicated by reversible perfusion defects. METHODS: Exercise or dobutamine stress tests with perfusion scintigraphy were performed in 1,173 patients with abnormal T-waves on their baseline electrocardiograms. The results of perfusion scintigraphy were compared in patients with and without stress-induced T-wave normalization. RESULTS: Only 33 of 270 patients with reversible perfusion defects (12.2%) had T-wave normalization during stress while 76.4% of 140 patients who had T-wave normalization during stress did not have a reversible perfusion defect. Results were similar for patients who did or did not reach 85% of their maximal predicted heart rate, for patients with and without Q-wave infarction on the baseline EKG and for patients who did or did not have ischemic ST-segment depression during stress. CONCLUSIONS: T-wave normalization during stress testing has low sensitivity and poor positive predictive value for stress-induced reversible myocardial ischemia.

Invasive assessment of mitral regurgitation: comparison of hemodynamic parameters.

OBJECTIVES: We sought to analyze several new hemodynamic characteristics which address the interplay of left atrial (LA) and left ventricular (LV) pressures, as well as to re-analyze several other V wave characteristics employed in the determination of mitral regurgitation (MR) severity in order to determine which, if any, had adequate correlation with grade of MR for clinical utility. BACKGROUND: Invasive assessment of mitral regurgitation includes analysis of intracardiac pressures and LV angiography. The V wave, when obtained from the pulmonary capillary wedge position (PCWP), and its various characteristics are believed to be of limited value for prediction of MR severity. METHOD: We analyzed the transeptal pressure tracings of patients with various degrees of MR. Several relationships from the simultaneous pressure-time curves of the LA and LV were defined. Biplane left ventricular angiography was used to grade MR. Correlation between each parameter and MR grade was determined by calculating a Pearson correlation coefficient. RESULTS: The ratio of the area under the V wave to the LV systolic area (V(a)/LV(a)) best correlates with the degree of MR with a Pearson correlation coefficient of 0.60. The V(a)/LV(a) was significantly lower in patients with 0-1+ MR compared to > or =2+ MR (0.14 vs. 0.23 p = 0.002). CONCLUSIONS: Invasive hemodynamic assessment of MR severity could be enhanced by calculating our new ratio, V(a)/LV(a), due to its ability to account for LV work that is lost to the LA with a proportional decrease in forward or useful LV work with progressively increasing severity of MR.

Is new ST-segment elevation after coronary artery bypass of clinical importance in the absence of perioperative myocardial infarction?

OBJECTIVE: To determine the frequency and significance of new ST-segment elevation during the early postoperative period after coronary artery bypass grafting (CABG) in patients without enzymatic or electrocardiogram evidence of perioperative myocardial infarction (MI). METHODS: Pre- and early postoperative electrocardiograms were reviewed in 506 patients undergoing CABG in whom MI was excluded by the absence of new Q waves or left bundle branch block and a peak postoperative troponin I less than 10 ng/mL. RESULTS: New ST-segment elevation of 0.1 mV or greater was observed in 64 patients (12.6%). Patients with and without ST-segment elevation did not differ with regard to age, prior coronary artery bypass, number of grafts, use of the internal mammary artery, incidence of postoperative atrial fibrillation, length of stay in the intensive care unit, duration of hospitalization, or 30-day mortality. CONCLUSIONS: ST-segment elevation not due to perioperative MI is common after CABG but is not associated with increased postoperative morbidity or mortality.