Therapeutic Controversies in the Medical Management of Valvular Heart Disease

Advances in diagnosis and treatment of mechanical hemolysis following percutaneous interventional for valvular heart diseases

Valvular heart disease is one of the common heart diseases in clinical practice, characterized by valve stenosis and/or incomplete closure. At present, drug therapy, surgery, and emerging percutaneous intervention therapy are the main treating methods for heart valve disease. Although the research and development of percutaneous intervention therapy devices is relatively mature, there are still problems such as postoperative mechanical hemolysis. The occurrence of mechanical hemolysis is associated with factors such as excessive shear stress experienced by red blood cells, direct interaction between red blood cells and the heart and valve surfaces, and thrombus formation. Furthermore, the presence of postoperative infection and other hemolytic diseases can also affect the occurrence of mechanical hemolysis. Although most patients are asymptomatic when hemolysis occurs, there are still critical cases. This type of hemolysis can accelerate the deterioration of the condition, and even endanger life in severe cases. Therefore, elucidating the background, pathogenesis, epidemiology, and related clinical research progress of mechanical hemolysis after percutaneous intervention therapy for valvular heart disease is of great significance for guiding the standardized diagnosis and treatment of the disease.

Surface Modification of Decellularized Heart Valve by the POSS-PEG Hybrid Hydrogel to Prepare a Composite Scaffold Material with Anticalcification Potential

Tissue-engineered heart valves (TEHVs) are the most promising replacement for heart valve transplantation. Decellularized heart valve (DHV) is one of the most common scaffold materials for TEHVs. In actual clinical applications, the most widely used method for treating DHV is cross-linking it with glutaraldehyde, but this method could cause serious problems such as calcification. In this study, we introduced polyhedral oligomeric silsesquioxane (POSS) nanoparticles into a poly(ethylene glycol) (PEG) hydrogel to prepare a POSS-PEG hybrid hydrogel, and then coated them on the surface of DHV to prepare the composite scaffold. The chemical structures, microscopic morphologies, cell compatibilities, blood compatibilities, and anticalcification properties were further investigated. Experimental results showed that the composite scaffold had good blood compatibility and excellent cell compatibility and could promote cell adhesion and proliferation. In vivo and in vitro anticalcification experiments showed that the introduction of POSS nanoparticles could reduce the degree of calcification significantly and the composite scaffold had obvious anticalcification ability. The DHV surface-coated with the POSS-PEG hybrid hydrogel is an alternative scaffold material with anticalcification potential for an artificial heart valve, which provides an idea for the preparation of TEHVs.

Effect of β-blocker on patients with moderate functional mitral regurgitation undergoing surgical aortic valve replacement

AIMS

The optimal treatment for severe aortic valve disease complicated with moderate function mitral regurgitation (FMR) remains controversial. Although isolated surgical aortic valve replacement (SAVR) is reasonable, previous studies also show that moderate FMR might deteriorate after surgical treatment and result in poorer prognosis. Because the left ventricular remodelling plays a critical role in the development of FMR, these patients might potentially benefit from the administration of β-blocker (BB). Unfortunately, relevant clinical evidence is lacking. This study aimed to investigate the impact of post-operative administration of BB on the outcomes of moderate FMR patients undergoing isolated SAVR.

METHODS

In this single-centre cohort study, patients who underwent isolated SAVR and complicated with pre-operative moderate FMR during 2010 and 2019 at our centre were retrospectively recruited. Patients were divided into two groups according to postoperative administration of BB (BB group vs. control group). The cumulative survival rates were calculated using the Kaplan-Meier method and tested by the log-rank test, followed by inverse probability treatment weighting (IPTW) analysis to further control the between-group imbalances. The primary outcome was the major adverse cardiovascular and cerebrovascular events (MACCE), a composite endpoint of all-cause death, repeat heart valve surgery, non-fatal myocardial infarction, stroke, and hospitalization for heart failure.

RESULTS

A total of 165 patients were enrolled, 57 (34.6%) of whom were female, and the mean age was 59.2 ± 12.2 years. Eighty (48.5%) patients received post-operative BB therapy. The median follow-up time was 18.4 months. The administration of BB was not associated with lower risk of MACCE [hazard ratio (HR): 0.68, 95% confidence interval (CI): 0.29-1.62, P = 0.388] or all-cause death (HR: 1.03, 95% CI: 0.30-0.56, P = 0.967). In the IPTW dataset, the total number of patients were 326.89, and the outcomes regarding the risk of MACCE (HR: 0.79, 95% CI: 0.31-1.97, P = 0.607) and all-cause death (HR: 1.33, 95% CI:0.35-5.05, P = 0.674) were in line with the unmatched analysis. The follow-up echocardiographic results were available for 72.2% of the overall cohort, and the use of BB was observed to be associated with higher improvement rate of follow-up FMR according to the IPTW analysis (92.2% vs. 98.3%, P = 0.033).

CONCLUSIONS

The administration of BB after SAVR was not associated with lower risk of MACCE for patients of severe aortic valve disease complicated with moderate FMR, but was potentially beneficial for improving FMR.

Predictors of Mortality Following Aortic Valve Replacement in Aortic Stenosis Patients

Background: Understanding of the risk factors for the development of adverse outcomes after aortic valve replacement is necessary to develop timely preventive measures and to improve the results of surgical treatment. Methods: We analyzed patients with aortic stenosis (n = 742) who underwent surgical treatment in the period 2014−2020. The average age was 63 (57;69) years—men 58%, women 42%. Results: The hospital mortality rate was 3% (22 patients). The following statistically significant threshold values (cut-off points) were obtained in the ROC analysis: aortic cross-clamp time > 93 min AUC (CI) 0.676 (0.640−0.710), p = 0.010; cardiopulmonary bypass time > 144 min AUC (CI) 0.809 (0.778−0.837), p < 0.0001, hemoglobin before op <120 g/L. AUC (CI) 0.762 (0.728−0.793), p < 0.0001, hematocrit before op <39% AUC (CI) 0.755 (0.721−0.786), p < 0.001, end-diastolic dimension index >2.39 AUC (CI) 0.647 (0.607−0.686), p = 0.014, end-systolic dimension index > 1.68 AUC (CI) 0.657 (0.617−0.695), p = 0.009. Statistically significant independent predictors of hospital mortality were identified: BMI > 30 kg/m2 (OR 2.84; CI 1.15−7.01), ischemic heart disease (OR 3.65; CI 1.01−13.2), diabetes (OR 3.88; CI 1.38−10.9), frequent ventricular ectopy before operation (OR 9.78; CI 1.91−50.2), mitral valve repair (OR 4.47; CI 1.76−11.3), tricuspid valve repair (OR 3.06; CI 1.09−8.58), 3 and more procedures (OR 4.44; CI 1.67−11.8). Conclusions: The hospital mortality rate was 3%. The main indicators associated with the risk of death were: diabetes, overweight (body mass index more than 30 kg/m2), frequent ventricular ectopy before surgery, hemoglobin level below 120 g/L, hematocrit level below 39%, longer cardiopulmonary bypass time and aortic cross-clamp time, additional mitral and tricuspid valve interventions.