Addressing the Controversy of Estimating Pulmonary Arterial Pressure by Echocardiography.

BACKGROUND: There is currently controversy over whether echocardiography provides reliable estimations of pulmonary pressures. The objective of this study was to determine the factors influencing the accuracy and reliability of estimating right ventricular systolic pressure (RVSP) using echocardiography in patients with advanced lung disease or pulmonary arterial hypertension. METHODS: Between January 2001 and December 2012, 667 patients with advanced lung disease or pulmonary arterial hypertension underwent right heart catheterization and transthoracic echocardiography. Of those, 307 had both studies within 5 days of each other. The correlation and bias in estimating RVSP according to tricuspid regurgitation (TR) signal quality and reader expertise were retrospectively determined. Reasons for under- and overestimation were analyzed. The diagnostic performance of estimated RVSP, relative right ventricular size, eccentricity index, and tricuspid annular plane systolic excursion was compared for classifying patients with pulmonary hypertension (mean pulmonary artery pressure ≥ 25 mm Hg). RESULTS: Invasive mean and systolic pulmonary artery pressures were strongly correlated (R(2) = 0.95, P < .001), with mean pulmonary artery pressure = 0.60 × systolic pulmonary artery pressure + 2.1 mm Hg. Among patients undergoing right heart catheterization and transthoracic echocardiography within 5 days, level 3 readers considered only 61% of TR signals interpretable, compared with 72% in clinical reports. Overestimation in the clinical report was related mainly to not assigning peak TR velocity at the modal frequency and underestimation to overreading of uninterpretable signals. When the TR signal was interpretable, the areas under the curve for classifying pulmonary hypertension were 0.97 for RVSP and 0.98 for RVSP and eccentricity index (P > .05). When TR signals were uninterpretable, eccentricity index and right ventricular size were independently associated with pulmonary hypertension (area under the curve, 0.77). CONCLUSIONS: Echocardiography reliably estimates RVSP when attention is given to simple quality metrics.

Clinical and functional correlates of early microvascular dysfunction after heart transplantation.

BACKGROUND: Microvascular dysfunction is emerging as a strong predictor of outcome in heart transplant recipients. At this time, the determinants and consequences of early microvascular dysfunction are not well established. The objective of the study was to determine the risk factors and functional correlates associated with early microvascular dysfunction in heart transplant recipients. METHODS AND RESULTS: Sixty-three heart transplant recipients who had coronary physiology assessment, right heart catheterization, and echocardiography performed at the time of their first annual evaluation were included in the study. Microvascular dysfunction was assessed using the recently described index of microcirculatory resistance. The presence of microvascular dysfunction, predefined by an index of microcirculatory resistance >20, was observed in 46% of patients at 1 year. A history of acute rejection and undersized donor hearts were associated with microvascular dysfunction at 1 year, with odds ratio of 4.0 (1.3-12.8) and 3.6 (1.2-11.1), respectively. Patients with microvascular dysfunction had lower cardiac index (3.1±0.7 versus 3.5±0.7 L/min per m(2); P=0.02) and mild graft dysfunction measured by echocardiography-derived left and right myocardial performance indices ([0.54±0.09 versus 0.43±0.09; P<0.01] and [0.47±0.14 versus 0.32±0.05; P<0.01], respectively). Microvascular dysfunction was also associated with a higher likelihood of death, graft failure, or allograft vasculopathy at 5 years after transplant (hazard ratio, 2.52 [95% CI, 1.04-5.91]). CONCLUSIONS: A history of acute rejection during the first year and smaller donor hearts were identified as risk factors for early microvascular dysfunction. Microvascular dysfunction assessed using index of microcirculatory resistances at 1 year was also associated with worse graft function and possibly worse clinical outcomes.

Changing trends in infectious disease in heart transplantation.

BACKGROUND: During the past 25 years, advances in immunosuppression and the use of selective anti-microbial prophylaxis have progressively reduced the risk of infection after heart transplantation. This study presents a historical perspective of the changing trends of infectious disease after heart transplantation. METHODS: Infectious complications in 4 representative eras of immunosuppression and anti-microbial prophylaxis were analyzed: (1) 38 in the pre-cyclosporine era (1978-1980), (2) 72 in the early cyclosporine era (1982-1984), where maintenance immunosuppression included high-dose cyclosporine and corticosteroid therapy; (3) 395 in the cyclosporine era (1988-1997), where maintenance immunosuppression included cyclosporine, azathioprine, and lower corticosteroid doses; and (4) 167 in the more recent era (2002-2005), where maintenance immunosuppression included cyclosporine and mycophenolate mofetil. RESULTS: The overall incidence of infections decreased in the 4 cohorts from 3.35 episodes/patient to 2.03, 1.35, and 0.60 in the more recent cohorts (p < 0.001). Gram-positive bacteria are emerging as the predominant cause of bacterial infections (28.6%, 31.4%, 51.0%, 67.6%, p = 0.001). Cytomegalovirus infections have significantly decreased in incidence and occur later after transplantation (88 +/- 77 days, pre-cyclosporine era; 304 +/- 238 days, recent cohort; p < 0.001). Fungal infections also decreased, from an incidence of 0.29/patient in the pre-cyclosporine era to 0.08 in the most recent era. A major decrease in Pneumocystis jiroveci and Nocardia infections has also occurred. CONCLUSIONS: The overall incidence and mortality associated with infections continues to decrease in heart transplantation and coincides with advances in immunosuppression, the use of selective anti-microbial prophylaxis, and more effective treatment regimens.