The adult heart contains small populations of multipotent cardiac progenitor cells (CPC) that present a convenient and efficient resource for treatment of myocardial infarction. Several clinical studies of direct CPC delivery by injection have already been performed but showed low engraftment rate that limited beneficial effects of procedure. «Cell sheet» technology has been developed to facilitate longer retention of grafted cells and show new directions for cell-based therapy using this strategy. In this study we hypothesized that СPC-based cell sheet transplantation could improve regeneration after myocardial infarction. We demonstrated that c-kit+ CPC were able to form cell sheets on temperature-responsive surfaces. Cell sheet represented a well-organized structure, in which CPC survived, retained ability to proliferate, expressed progenitor cell marker Gata-4 formed connexin-43+ gap junctions, and were surrounded by significant amount of extracellular matrix proteins. Transplantation of cell sheets after myocardial infarction resulted in CPC engraftment as well as their proliferation, migration, and differentiation; cell sheets also stimulated neovascularization and cardiomyocyte proliferation in underlining myocardium and ameliorated left ventricular remodeling. Obtained data strongly supported potential use of CPC sheet transplantation for repair of damaged heart.
Background
Heart failure with preserved ejection fraction (HFpEF) is frequently complicated by pulmonary hypertension (PH). A pulmonary vascular contribution could be considered as a substantial therapeutic target in HFpEF and PH and combined pre- and postcapillary PH (Cpc-PH).
Methods
We enrolled 50 patients with HFpEF and Cpc-PH who were determined by echocardiography to have pulmonary artery systolic pressure (PASP) > 40 mmHg, pulmonary vascular resistance > 3 Wood units, and/or transpulmonary gradient > 15 mmHg.
Results
The patients were assigned to the phosphodiesterase 5 (PDE5) inhibitor sildenafil group (25 mg TID for 3 months followed by 50 mg TID for 3 months; n = 30) or the control group (n = 20). In the sildenafil group after 6 months, the 6-min walk distance increased by 50 m (95% CI, 36 to 64 m); substantial improvement in NYHA functional class and exercise capacity during diastolic stress test were revealed; decreases in early mitral inflow to mitral annulus relaxation velocities ratio by 2.4 (95% CI, − 3.3 to − 1.4) and PASP by 17.0 mmHg (95% CI, 20.4 to 13.5) were observed; right ventricular systolic function (M-mode tricuspid annular plane systolic excursion) increased by 0.42 cm (95% CI, 0.32 to 0.52 cm; P < 0.01 for all). No changes occurred in the control group.
Conclusions
In a subset of patients with HFpEF and Cpc-PH assessed by echocardiography, PDE5 inhibition was associated with an improvement in exercise capacity, pulmonary haemodynamic parameters, and right ventricular function. The role of sildenafil needs to be considered in randomized trials in selected patients with HFpEF with invasively confirmed Cpc-PH.
Trial registration
Russian National Information System of Research, Development and Technology Data of Civilian Usage (NIS, https://rosrid.ru), registration number 01201257849. Registered 20 April 2012.
This manuscript adheres to the CONSORT guidelines.
AimsThe purpose of this pilot study was to assess the potential usefulness of diastolic stress test (DST) echocardiography in patients with suspected heart failure with preserved ejection fraction (HFpEF).Methods and resultsPatients with suspected HFpEF (left ventricular ejection fraction ≥ 50%, exertional dyspnoea, septal E/e′ at rest 9–14, and N‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP) at rest < 220 pg/mL; n = 13) and a control group constituted from asymptomatic patients with arterial hypertension (n = 19) and healthy subjects (n = 18) were included. All patients were analysed by two‐dimensional and Doppler echocardiography at rest and during exercise (DST) and underwent cardiopulmonary exercise testing and NT‐proBNP analysis during exercise. HFpEF during exercise was defined as exertional dyspnoea and peak VO2 ≤ 20.0 mL/min/kg. In patients with suspected HFpEF at rest, 84.6% of these patients developed HFpEF during exercise, whereas in the group of asymptomatic patients with hypertension and healthy subjects, the rate of developed HFpEF during exercise was 0%. Regarding the diagnostic performance of DST to detect HFpEF during exercise, an E/e′ ratio >15 during exercise was the most accurate parameter to detect HFpEF (accuracy 86%), albeit a low sensitivity (45.5%). Nonetheless, combining E/e′ with tricuspid regurgitation (TR) velocity > 2.8 m/s during exercise provided a significant increase in the sensitivity to detect patients with HFpEF during exercise (sensitivity 72.7%, specificity 79.5%, and accuracy 78%). Consistent with these findings, an increase of E/e′ was significantly linked to worse peak VO2, and the combination of an increase of both E/e′ and TR velocity was associated with elevated NT‐proBNP values during exercise.ConclusionsThe findings of this pilot study suggest that DST using E/e′ ratio and TR velocity could be of potential usefulness to diagnose HFpEF during exercise in patients with suspected HFpEF at rest.
Heart failure withpreserved ejection fraction (HFpEF) is a severe disease with an often unfavorable outcome. The prevalence of HFpEF continues to increase, while effective treatment options remain elusive. All the medical strategies used toimprove the outcome in a heart failure with reduced ejection fraction proved ineffective in HFpEF, which was probably due to the different mechanisms ofdevelopment of these two types of heart failure and the diversity of the HFpEF phenotypes. According to the current paradigm of HFpEF development, a chronic mild pro-inflammatory statecauses a coronary microvascular endothelial inflammation, with further myocardial fibrosis and diastolic dysfunction progression. This inflammatory paradigm of HFpEF has been confirmed with someevidence, and suppressing the inflammation may become a novel strategy for treating and managing HFpEF. This review summarizes current concepts about a microvascular inflammation in hypertrophied myocardium and provides a translational perspective of the anti-inflammatory and immunomodulatory approaches in HFpEF.
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