Sildenafil treatment in established right ventricular dysfunction improves diastolic function and attenuates interstitial fibrosis independent from afterload

Right ventricular (RV) function is an important determinant of prognosis in congenital heart diseases, pulmonary hypertension, and heart failure. Preventive sildenafil treatment has been shown to enhance systolic RV function and improve exercise capacity in a model of fixed RV pressure load. However, it is unknown whether sildenafil has beneficial effects when treatment is started in established RV dysfunction, which is clinically more relevant. Our aim was to assess the effects of sildenafil treatment on RV function and fibrosis in a model of established RV dysfunction due to fixed afterload. Rats were subjected to pulmonary artery banding (PAB), which induced RV dysfunction after 4 wk, characterized by reduced exercise capacity, decreased tricuspid annular plane systolic excursion, and RV dilatation. From week 4 onward, 50% of rats were treated with sildenafil (100 mg.kg(-1).day(-1), n = 9; PAB-SIL group) or vehicle (n = 9; PAB-VEH group). At 8 wk, exercise capacity was assessed using cage wheels, and RV function was assessed using invasive RV pressure-volume measurements under anesthesia. Sildenafil treatment, compared with vehicle, improved RV ejection fraction (44 +/- 2% vs. 34 +/- 2%, P <0.05, PAB-SIL vs. PAB-VEH groups), reduced RV end-diastolic pressure (2.3 +/- 0.5 vs. 5.1 +/- 0.9 mmHg, P <0.05), and RV dilatation (end-systolic volume: 468 +/- 45 vs. 643 +/- 71 mu l, P = 0.05). Sildenafil treatment also attenuated RV fibrosis (30 +/- 6 vs. 17 +/- 3%, P <0.05) but did not affect end-systolic elastance, exercise capacity, or PKG or PKA activity. In conclusion, sildenafil improves RV diastolic function and attenuates interstitial fibrosis in rats with established RV dysfunction, independent from afterload. These results indicate that sildenafil treatment has therapeutic potential for established RV dysfunction

Clinical symptoms of right ventricular failure in experimental chronic pressure load are associated with progressive diastolic dysfunction

Background: Right ventricular failure (RVF) due to pressure load is a major cause of death in congenital heart diseases and pulmonary hypertension. The mechanisms of RVF are unknown. We used an experimental approach based upon clinical signs of RVF to delineate functional and biological processes associated with RVF. Methods and results: Wistar rats were subjected to a pulmonary artery banding (PAB n = 12) or sham surgery (CON, n = 7). After 52 5 days, 5/12 PAB rats developed clinical symptoms of RVF (inactivity, ruffled fur, dyspnea, ascites) necessitating termination (PAR + CF). We compared these to PAR rats with RVF without clinical symptoms (PAB). PAB resulted in reduced cardiac output, RV stroke volume, TAPSE, and increased end diastolic pressure (all p <0.05 vs. CON) in all rats, but PAB + CF rats were significantly more affected than PAR, despite similar pressure load (p = ns). Pressure-volume analysis showed enhanced contractility (end systolic elastance) in PAB and PAR + CF, but diastolic function (end diastolic elastance, end diastolic pressure) deteriorated especially in PAB + CF. In PAB + CF capillary density was lower than in PAR. Gene-array analysis revealed down-regulation of both fatty acid oxidation and carbohydrate metabolism in PAB + CF. Conclusion: Chronic PAR led to different degrees of RVF, with half of the rats developing severe clinical symptoms of RVF, associated with progressive deterioration of diastolic function, hypoxia-prone myocardium, increased response to oxidative stress and suppressed myocardial metabolism. This model represents clinical RVF and allows for unraveling of mechanisms involved in the progression from RV adaptation to RV failure and the effect of intervention on these mechanisms. (C) 2014 Elsevier Ltd. All rights reserved

Incidence, Causes, and Outcomes Associated With Urgent Implantation of a Supplementary Valve During Transcatheter Aortic Valve Replacement.

Importance Transcatheter aortic valve replacement (TAVR) failure is often managed by an urgent implantation of a supplementary valve during the procedure (2-valve TAVR [2V-TAVR]). Little is known about the factors associated with or sequelae of 2V-TAVR. Objective To examine the incidence, causes, and outcomes of 2V-TAVR. Design, Setting, and Participants A retrospective cohort study was performed using data from an international registry of 21 298 TAVR procedures performed from January 1, 2014, through February 28, 2019. Among the 21 298 patients undergoing TAVR, 223 patients (1.0%) undergoing 2V-TAVR were identified. Patient-level data were available for all the patients undergoing 2V-TAVR and for 12 052 patients (56.6%) undergoing 1V-TAVR. After excluding patients with missing 30-day follow-up or data inconsistencies, 213 2V-TAVR and 10 010 1V-TAVR patients were studied. The 2V-TAVR patients were compared against control TAVR patients undergoing a 1-valve TAVR (1V-TAVR) using 1:4 17 propensity score matching. Final analysis included 1065 (213:852) patients. Exposures Urgent implantation of a supplementary valve during TAVR. Main Outcomes and Measures Mortality at 30 days and 1 year. Results The 213 patients undergoing 2V-TAVR had similar age (mean [SD], 81.3 [0.5] years) and sex (110 [51.6%] female) as the 10 010 patients undergoing 1V-TAVR (mean [SD] age, 81.2 [0.5] years; 110 [51.6%] female). The 2V-TAVR incidence decreased from 2.9% in 2014 to 1.0% in 2018 and was similar between repositionable and nonrepositionable valves. Bicuspid aortic valve (odds ratio [OR], 2.20; 95% CI, 1.17-4.15; P = .02), aortic regurgitation of moderate or greater severity (OR, 2.02; 95% CI, 1.49-2.73; P < .001), atrial fibrillation (OR, 1.43; 95% CI, 1.07-1.93; P = .02), alternative access (OR, 2.59; 95% CI, 1.72-3.89; P < .001), early-generation valve (OR, 2.32; 95% CI, 1.69-3.19; P < .001), and self-expandable valve (OR, 1.69; 95% CI, 1.17-2.43; P = .004) were associated with higher 2V-TAVR risk. In 165 patients (80%), the supplementary valve was implanted because of residual aortic regurgitation after primary valve malposition (94 [46.4%] too high and 71 [34.2%] too low). In the matched 2V-TAVR vs 1V-TAVR cohorts, the rate of device success was 147 (70.4%) vs 783 (92.2%) (P < .001), the rate of coronary obstruction was 5 (2.3%) vs 3 (0.4%) (P = .10), stroke rate was 9 (4.6%) vs 13 (1.6%) (P = .09), major bleeding rates were 25 (11.8%) vs 46 (5.5%) (P = .03) and annular rupture rate was 7 (3.3%) vs 3 (0.4%) (P = .03). The hazard ratios for mortality were 2.58 (95% CI, 1.04-6.45; P = .04) at 30 days, 1.45 (95% CI, 0.84-2.51; P = .18) at 1 year, and 1.20 (95% CI, 0.77-1.88; P = .42) at 2 years. Nontransfemoral access and certain periprocedural complications were independently associated with higher risk of death 1 year after 2V-TAVR. Conclusions and Relevance In this cohort study, valve malposition was the most common indication for 2V-TAVR. Incidence decreased over time and was low overall, although patients with a bicuspid or regurgitant aortic valve, nontransfemoral access, and early-generation or self-expandable valve were at higher risk. These findings suggest that compared with 1V-TAVR, 2V-TAVR is associated with high burden of complications and mortality at 30 days but not at 1 year

Transcatheter Replacement of Transcatheter Versus Surgically Implanted Aortic Valve Bioprostheses

Background: Surgical aortic valve replacement and transcatheter aortic valve replacement (TAVR) are now both used to treat aortic stenosis in patients in whom life expectancy may exceed valve durability. The choice of initial bioprosthesis should therefore consider the relative safety and efficacy of potential subsequent interventions. Objectives: The aim of this study was to compare TAVR in failed transcatheter aortic valves (TAVs) versus surgical aortic valves (SAVs). Methods: Data were collected on 434 TAV-in-TAV and 624 TAV-in-SAV consecutive procedures performed at centers participating in the Redo-TAVR international registry. Propensity score matching was applied, and 330 matched (165:165) patients were analyzed. Principal endpoints were procedural success, procedural safety, and mortality at 30 days and 1 year. Results: For TAV-in-TAV versus TAV-in-SAV, procedural success was observed in 120 (72.7%) versus 103 (62.4%) patients (p = 0.045), driven by a numerically lower frequency of residual high valve gradient (p = 0.095), ectopic valve deployment (p = 0.081), coronary obstruction (p = 0.091), and conversion to open heart surgery (p = 0.082). Procedural safety was achieved in 116 (70.3%) versus 119 (72.1%) patients (p = 0.715). Mortality at 30 days was 5 (3%) after TAV-in-TAV and 7 (4.4%) after TAV-in-SAV (p = 0.570). At 1 year, mortality was 12 (11.9%) and 10 (10.2%), respectively (p = 0.633). Aortic valve area was larger (1.55 ± 0.5 cm2 vs. 1.37 ± 0.5 cm2; p = 0.040), and the mean residual gradient was lower (12.6 ± 5.2 mm Hg vs. 14.9 ± 5.2 mm Hg; p = 0.011) after TAV-in-TAV. The rate of moderate or greater residual aortic regurgitation was similar, but mild aortic regurgitation was more frequent after TAV-in-TAV (p = 0.003). Conclusions: In propensity score–matched cohorts of TAV-in-TAV versus TAV-in-SAV patients, TAV-in-TAV was associated with higher procedural success and similar procedural safety or mortality

Repeat Transcatheter Aortic Valve Replacement for Transcatheter Prosthesis Dysfunction.

BACKGROUND Transcatheter aortic valve replacement (TAVR) use is increasing in patients with longer life expectancy, yet robust data on the durability of transcatheter heart valves (THVs) are limited. Redo-TAVR may play a key strategy in treating patients in whom THVs fail. OBJECTIVES The authors sought to examine outcomes following redo-TAVR. METHODS The Redo-TAVR registry collected data on consecutive patients who underwent redo-TAVR at 37 centers. Patients were classified as probable TAVR failure or probable THV failure if they presented within or beyond 1 year of their index TAVR, respectively. RESULTS Among 63,876 TAVR procedures, 212 consecutive redo-TAVR procedures were identified (0.33%): 74 within and 138 beyond 1 year of the initial procedure. For these 2 groups, TAVR-to-redo-TAVR time was 68 (38 to 154) days and 5 (3 to 6) years. The indication for redo-TAVR was THV stenosis in 12 (16.2%) and 51 (37.0%) (p = 0.002) and regurgitation or combined stenosis-regurgitation in 62 (83.8%) and 86 (62.3%) (p = 0.028), respectively. Device success using VARC-2 criteria was achieved in 180 patients (85.1%); most failures were attributable to high residual gradients (14.1%) or regurgitation (8.9%). At 30-day and 1-year follow-up, residual gradients were 12.6 ± 7.5 mm Hg and 12.9 ± 9.0 mm Hg; valve area 1.63 ± 0.61 cm2 and 1.51 ± 0.57 cm2; and regurgitation ≤mild in 91% and 91%, respectively. Peri-procedural complication rates were low (3 stroke [1.4%], 7 valve malposition [3.3%], 2 coronary obstruction [0.9%], 20 new permanent pacemaker [9.6%], no mortality), and symptomatic improvement was substantial. Survival at 30 days was 94.6% and 98.5% (p = 0.101) and 83.6% and 88.3% (p = 0.335) at 1 year for patients presenting with early and late valve dysfunction, respectively. CONCLUSIONS Redo-TAVR is a relatively safe and effective option for selected patients with valve dysfunction after TAVR. These results are important for applicability of TAVR in patients with long life expectancy in whom THV durability may be a concern