Thananya Boonyasirinant

Prevalence and prognosis of myocardial scar in patients with known or suspected coronary artery disease and normal wall motion

BackgroundSome patients may have normal wall motion after myocardial infarction. The aim of this study was to determine the prevalence and prognosis of patients with myocardial scar in the absence of abnormal wall motion. We studied patients with suspected or known coronary artery disease (CAD) who were referred for cardiovascular magnetic resonance (CMR) for the assessment of global and regional cardiac function and late gadolinium enhancement (LGE) and had normal left ventricular wall motion. Prognostic value was determined by the occurrence of hard endpoints (cardiac death and nonfatal myocardial infarction) and major adverse cardiac events (MACE) which also included hospitalization due to unstable angina or heart failure or life threatening ventricular arrhythmia.ResultsA total 1148 patients (70.3%) were studied. LGE was detected in 104 patients (9.1%). Prevalence of LGE increased in patients with increased left ventricular mass. Average follow-up time was 955 ± 542 days. LGE was the strongest predictor for hard endpoints and MACE.ConclusionLGE was detected in 9.1% of patients with suspected or known CAD and normal wall motion. LGE was the strongest predictor of significant cardiac events.

Comparison of the region-based and pixel-wise methods for cardiac T2* analysis in 50 transfusion-dependent Thai thalassemia patients.

Purpose: To compare the observer variability of the conventional region-based (RB) to the typical and proposed pixel-wise (PW) methods for cardiac T2* analysis in thalassemia patients. Design and Methods: Fifty thalassemia major patients were enrolled for the study. Short-axis bright- and black-blood sequences were acquired and analyzed using the RB and PW methods. Regions were defined using the whole septum (WS) or partial septum (PS). From the same PS region, results were reported by mean (PS-PW) and median (MPS-PW). Intraobserver and interobserver variabilities were investigated on all data set by 2 independent observers blinded to the result. Results: The T2* values from the PS-PW and MPS-PW methods were comparable to the conventional WS-RB method on both scanning techniques. When comparing the interobserver variability from the WS-RB to the PS-PW method, the coefficient of variation of the PS-PW method was equivalent (4.5% vs 4.7%, P = NS) for the bright-blood technique but 31% lower (4.0% vs 2.8%, P = 0.21) for the black-blood technique. The proposed MPS-PW method performed even better with respect to the conventional WS-RB method, decreasing interobserver coefficient of variation by 24% (4.5% vs 3.5%, P = 0.08) and 42% (4.0% vs 2.4%, P = 0.02), respectively. Intraobserver reproducibility followed the same trend. Conclusions: The proposed PW method using the median of T2* values calculated from partial interventricular septum region provided lower intraobserver and interobserver variabilities compared with the conventional RB or typical PW methods.

Magnetic resonance imaging abnormalities in right ventricular outflow tract tachycardia and the prediction of radiofrequency ablation outcome.

Background: Recent reports have shown abnormalities on cardiac magnetic resonance imaging (MRI) in patients with right ventricular outflow tract (RVOT) tachycardia.

Prognostic significance of left ventricular mass by magnetic resonance imaging study in patients with known or suspected coronary artery disease.

Objectives To study the prognostic value of left ventricular mass (LVM) assessed by cardiac magnetic resonance in patients with known or suspected coronary artery disease. Methods We studied patients who were referred for cardiac magnetic resonance for the assessment of cardiac function, LVM, and late gadolinium enhancement (LGE). Prognostic value was determined by the occurrence of hard cardiac endpoint, including death or nonfatal myocardial infarction and major adverse cardiac event, which also included hospitalization due to heart failure or unstable angina and life-threatening ventricular arrhythmia. We analyzed prognostic value of LVM index stratified by quintiles and specific percentile ranges. Results A total of 2194 patients with the average age of 65 ± 11 years were enrolled. Average left ventricular ejection fraction and LVM index were 59.2 ± 19.4% and 56.6 ± 21.3 g/m2, respectively. LGE was present in 785 patients (35.8%). Average follow-up duration was 926 ± 582 days. Hard events and major adverse cardiac events occurred in 92 (4.2%) and 210 patients (9.6%). Cox regression analysis showed that left ventricular ejection fraction, LGE, and LVM index were independent predictors for clinical events. The highest quartile of LVM index had the greatest risk for clinical events independent of other factors, including left ventricular ejection fraction and LGE. Conclusion LVM index by cardiac magnetic resonance is an independent predictor for cardiovascular event in patients with known or suspected coronary artery disease.

Correlation between aortic stiffness and left atrial volume index in hypertensive patients

Abstract Background: Both arterial stiffness and left atrial volume index are crucial predictors of cardiovascular outcomes in hypertensive patients. The correlation between these two factors has not been previously well established in hypertensive population. Objectives: To determine the correlation between arterial stiffness and left atrial volume index in hypertensive patients. Methods and results: The study was performed in 111 consecutive hypertensive patients (49.5% male, mean age 70.8 ± 10.3 years) undergoing cardiac magnetic resonance imaging (CMR). Arterial stiffness was determined by pulse wave velocity in the thoracic aorta by velocity-encoded imaging. Left atrial volume was assessed by biplane area-length method. Pulse wave velocity was significantly correlated with left atrial volume index in univariate analysis (r = 0.20, p = 0.032). In multivariate analysis, pulse wave velocity, coronary artery disease and left ventricular mass remain independent predictors (β = 1.01, p = 0.02). Conclusion: Increased arterial stiffness correlates with left atrial enlargement in hypertensive patients. The prevention of left atrial enlargement and subsequent complications by specific antihypertensive drugs with positive effect on aortic stiffness warrants further studies.

NT-proBNP levels in the evaluation of right ventricular dysfunction in patients with coronary artery disease and abnormal left ventricular wall motion: a magnetic resonance imaging study.

BackgroundData available on the correlation of N-terminal probrain natriuretic peptide (NT-proBNP) levels and right ventricular (RV) function in patients with coronary artery disease (CAD) are limited. ObjectiveTo determine the relation between plasma NT-proBNP and RV function in patients with CAD and abnormal left ventricular (LV) wall motion. MethodsThis is a cross-sectional study. We studied 176 patients with CAD and abnormal LV wall motion. All patients underwent cardiac magnetic resonance imaging for the assessment of LV and RV function and plasma NT-proBNP analysis on the same day. Multivariable analysis was performed to evaluate the independent factors associated with RV dysfunction. Receiver-operating characteristic analysis was used to assess the use of NT-proBNP levels for the diagnosis of LV and RV dysfunction. ResultsAverage LV ejection fraction (LVEF) and RV ejection fraction were 37.6 and 52.0%, respectively. Median levels of NT-proBNP were 978 pg/ml. Log NT-proBNP levels had a positive correlation with age, LV and RV volume, LV and RV mass, and had a negative correlation with body size, creatinine clearance, LVEF, and RV ejection fraction. From a multivariable analysis, log NT-proBNP levels and LVEF were independently associated with RV dysfunction. From receiver-operating characteristic analysis, NT-proBNP at the levels of 1706 and 378 pg/ml was shown to detect RV dysfunction and LV dysfunction at an accuracy of 80.7 and 77.8% and area under the curve of 0.837 and 0.765, respectively. ConclusionNT-proBNP levels can be used to diagnose RV dysfunction in patients with CAD and abnormal LV wall motion.