Myocardial work assessment in severe aortic stenosis undergoing transcatheter aortic valve replacement.

AIMS: Myocardial work is a novel echocardiographic algorithm that corrects speckle-tracking-derived global longitudinal strain (GLS) for afterload using non-invasive systolic blood pressure as a surrogate for left ventricular systolic pressure (LVSP). Yet, in patients with severe aortic stenosis, non-invasive systolic blood pressure does not equal LVSP. METHODS AND RESULTS: We evaluated 35 patients with severe aortic stenosis who underwent transcatheter aortic valve replacement (TAVR). Transthoracic echocardiography, including myocardial mechanics, was performed pre- and post-TAVR. We performed simultaneous echocardiographic and cardiac catheterization measurements in 23 of the 35 patients at the time of TAVR. Peak and mean aortic gradients were calculated from echocardiographic and cardiac catheterization data. Peak-to-peak LV-aortic gradient correlated highly with mean LV-aortic gradient (r = 0.96); measured LVSP correlated highly with our novel method of non-invasively estimated LVSP (non-invasive systolic blood pressure cuff + Doppler-derived mean aortic gradient, r = 0.92). GLS improved from pre- to post-TAVR (-14.2% ± 4.3 vs. -15.1% ± 3.2), and myocardial work reduced from corrected pre-TAVR to post-TAVR (global work index: 1856.2 mmHg% ± 704.6 vs. 1534.8 ± 385.0). CONCLUSION: We propose that non-invasive assessment of myocardial work can be reliably performed in aortic stenosis by the addition of mean aortic gradient to non-invasive systolic blood pressure. From this analysis, we note the novel and unique finding that GLS can improve as myocardial work reduces post-TAVR in patients with severe aortic stenosis. Both GLS and myocardial work post-TAVR remain below normal values, requiring further studies.

Myocardial Work Index: A Novel Method for Assessment of Myocardial Function in South Asian Recreational Athletes.

PURPOSE: We used a novel noninvasive method based on speckle-tracking echocardiography to evaluate myocardial performance in South Asian recreational athletes who completed a half marathon. METHODS: Transthoracic echocardiography was performed on 24 recreational athletes 48 hours before they took part in a half marathon (premarathon), within 2 hours of half marathon completion (postmarathon), and 72 hours after completion. Clinical, laboratory, and echocardiographic variables were collected. Speckle-tracking echocardiography was performed in all subjects to characterize myocardial mechanics. RESULTS: Mean age of participants was 41.8 ± 7.4 years, and 23 (95.8%) were male. No subject had a prior history of coronary artery disease. Significant changes in pre- and postmarathon values suggested myocardial injury, including an increase in mean brain natriuretic peptide (BNP), an increase in left atrial volume, and an overall reduction in peak left ventricular global longitudinal strain. All subjects had a similar value of global work index, the average myocardial work, premarathon. Global work index did not change in 11 patients (Group 1), and global work index increased in 13 patients (Group 2) immediately postmarathon. Group 2 patients were noted to have higher heart rate, lower end-diastolic and end-systolic volumes, and higher BNP levels, suggesting myocardial stress. CONCLUSIONS: South Asian athletes completing a half marathon exhibited two different responses to the cardiac stress of the half marathon, as outlined by the use of myocardial work indices, a novel method for assessing cardiac performance.

Role of Two-Dimensional Speckle-Tracking Echocardiography Strain in the Assessment of Right Ventricular Systolic Function and Comparison with Conventional Parameters.

Despite the already well-known role the right side of the heart plays in many diseases, right ventricular (RV) function has only recently been carefully considered. Echocardiography is the first-line diagnostic technique for the assessment of the right ventricle and right atrium, whereas cardiac magnetic resonance is considered the gold standard but is limited by cost and availability. According to the current guidelines, systolic RV function should be assessed by several conventional measurements, but the efficacy of these parameters as diagnostic and prognostic tools has been questioned by many authors. The development in recent years of myocardial deformation imaging techniques and their application to the right heart chambers has allowed deeper evaluation of the importance of RV function in the pathophysiology of a large number of cardiovascular conditions, but the real value of this new tool has not been completely clarified. The aim of this review is to provide a wide and careful analysis of findings available in the literature about the assessment of RV systolic function by strain measurements, comparing them with conventional parameters and evaluating their role in several clinical settings.

How accurate is the eyeball test?: a comparison of physician's subjective assessment versus statistical methods in estimating mortality risk after cardiac surgery.

BACKGROUND: In the era of increasing percutaneous treatment options for heart disease, the estimation of surgical risk has become a key factor in selecting optimal treatment strategies. Surgical risk has historically been estimated by physician's subjective assessment and more recently by statistical risk estimates. METHODS AND RESULTS: We studied 5099 consecutive patients who underwent cardiac surgery at Minneapolis Veterans Affairs Medical Center between 1993 and 2010. Operative mortality risk was estimated statistically by the Veterans Affairs mortality risk estimate and subjectively by cardiac surgeons before surgery. Observed mortality rate was 3.3% (168 deaths) at 1 month, 7.1% (360 deaths) at 1 year, and 18.5% (942 deaths) at 5 years after surgery. Physician's risk estimate (mean [SD], 5.6% [4.4]) and statistical risk estimate (4.3% [5.1]) had modest correlation (c-index, 0.56; P<0.001). Both methods modestly overestimated operative mortality risk. Statistical risk estimate was significantly better than physician's risk estimate in separating patients who died from those who survived at 30 days (c-index, 0.78 versus 0.73; P=0.003), at 1 year (c-index, 0.72 versus 0.61; P<0.001), and at 5 years (c-index, 0.72 versus 0.64; P<0.001) after surgery. Physician's risk estimate was higher than statistical risk estimate in all subgroups except high-risk patients. CONCLUSIONS: In patients undergoing cardiac surgery, statistical risk estimate is a better method to predict operative and long-term mortality compared with physician's subjective risk estimate. However, both methods modestly overestimate actual operative mortality risk.