Ana Gonzalez-Mansilla

Validation of Noninvasive Indices of Global Systolic Function in Patients With Normal and Abnormal Loading Conditions A Simultaneous Echocardiography Pressure-Volume Catheterization Study

Background—Noninvasive indices based on Doppler echocardiography are increasingly used in clinical cardiovascular research to evaluate left ventricular global systolic chamber function. Our objectives were to clinically validate ultrasound-based methods of global systolic chamber function to account for differences between patients in conditions of abnormal load, and to assess their sensitivity to load confounders. Methods and Results—Twenty-seven patients (8 dilated cardiomyopathy, 10 normal ejection fraction, and 9 end-stage liver disease) underwent simultaneous echocardiography and left heart catheterization with pressure-conductance instrumentation. The reference index, maximal elastance (Emax), was calculated from pressure–volume loop data obtained during acute inferior vena cava occlusion. A wide range of values were observed for left ventricular systolic chamber function (Emax: 2.8±1.0 mm Hg/mL), preload, and afterload. Among the noninvasive indices tested, the peak ejection intraventricular pressure difference showed the best correlation with Emax (R=0.75). A significant but weaker correlation with Emax was observed for ejection fraction (R=0.41), midwall fractional shortening (R=0.51), global circumferential strain (R=−0.53), and strain rate (R=−0.46). Longitudinal strain and strain rate failed to correlate with Emax, as did noninvasive single-beat estimations of this index. Principal component and multiple regression analyses demonstrated that peak ejection intraventricular pressure difference was less sensitive to load, whereas ejection fraction and longitudinal strain and strain rate were heavily influenced by afterload. Conclusions—Current ultrasound methods have limited accuracy to characterize global left ventricular systolic chamber function in a given patient. The Doppler-derived peak ejection intraventricular pressure difference should be preferred for this purpose because it best correlates with the reference index and is more robust in conditions of abnormal load.

Diastolic chamber properties of the left ventricle assessed by global fitting of pressure-volume data: improving the gold standard of diastolic function

In cardiovascular research, relaxation and stiffness are calculated from pressure-volume (PV) curves by separately fitting the data during the isovolumic and end-diastolic phases (end-diastolic PV relationship), respectively. This method is limited because it assumes uncoupled active and passive properties during these phases, it penalizes statistical power, and it cannot account for elastic restoring forces. We aimed to improve this analysis by implementing a method based on global optimization of all PV diastolic data. In 1,000 Monte Carlo experiments, the optimization algorithm recovered entered parameters of diastolic properties below and above the equilibrium volume (intraclass correlation coefficients = 0.99). Inotropic modulation experiments in 26 pigs modified passive pressure generated by restoring forces due to changes in the operative and/or equilibrium volumes. Volume overload and coronary microembolization caused incomplete relaxation at end diastole (active pressure > 0.5 mmHg), rendering the end-diastolic PV relationship method ill-posed. In 28 patients undergoing PV cardiac catheterization, the new algorithm reduced the confidence intervals of stiffness parameters by one-fifth. The Jacobian matrix allowed visualizing the contribution of each property to instantaneous diastolic pressure on a per-patient basis. The algorithm allowed estimating stiffness from single-beat PV data (derivative of left ventricular pressure with respect to volume at end-diastolic volume intraclass correlation coefficient = 0.65, error = 0.07 ± 0.24 mmHg/ml). Thus, in clinical and preclinical research, global optimization algorithms provide the most complete, accurate, and reproducible assessment of global left ventricular diastolic chamber properties from PV data. Using global optimization, we were able to fully uncouple relaxation and passive PV curves for the first time in the intact heart.

Tricuspid but not Mitral Regurgitation Determines Mortality After TAVI in Patients With Nonsevere Mitral Regurgitation

INTRODUCTION AND OBJECTIVES Many patients undergoing transcatheter aortic valve implantation (TAVI) have concomitant mitral regurgitation (MR) of moderate grade or less. The impact of coexistent tricuspid regurgitation (TR) remains to be determined. We sought to analyze the impact of moderate vs none-to-mild MR and its trend after TAVI, as well as the impact of concomitant TR and its interaction with MR. METHODS Multicenter retrospective study of 813 TAVI patients treated through the transfemoral approach with MR ≤ 2 between 2007 and 2015. RESULTS The mean age was 81 ± 7 years and the mean Society of Thoracic Surgeons score was 6.9% ± 5.1%. Moderate MR was present in 37.3% of the patients, with similar in-hospital outcomes and 6-month follow-up mortality to those with MR < 2 (11.9% vs 9.4%; P = .257). However, they experienced more rehospitalizations and worse New York Heart Association class (P = .008 and .001, respectively). Few patients (3.8%) showed an increase in the MR grade to > 2 post-TAVI. The presence of concomitant moderate/severe TR was associated with in-hospital and follow-up mortality rates of 13% and 34.1%, respectively, regardless of MR grade. Moderate-severe TR was independently associated with mortality (HR, 18.4; 95%CI, 10.2-33.3; P < .001). CONCLUSIONS The presence of moderate MR seemed not to impact short- and mid-term mortality post-TAVI, but was associated with more rehospitalizations. The presence of moderate or severe TR was associated with higher mortality. This suggests that a thorough evaluation of the mechanisms underlying concomitant mitral and tricuspid valve regurgitation should be performed to determine the best strategy for avoiding TAVI-related futility.

Stasis Mapping Using Ultrasound: A Prospective Study in Acute Myocardial Infarction

During the subacute phase of acute myocardial infarction (AMI), the incidence of left ventricular thrombosis (LVT) can be as high as 15% to 20%. A method for assessing the risk of LVT would be of particular value in the setting of AMI, because prophylactic anticoagulation must be balanced against