Background: SARS-CoV-2, the causal agent of COVID-19, enters human cells using the ACE2 (angiotensin-converting enzyme 2) protein as a receptor. ACE2 is thus key to the infection and treatment of the coronavirus. ACE2 is highly expressed in the heart and respiratory and gastrointestinal tracts, playing important regulatory roles in the cardiovascular and other biological systems. However, the genetic basis of the ACE2 protein levels is not well understood. Methods: We have conducted the largest genome-wide association meta-analysis of plasma ACE2 levels in >28 000 individuals of the SCALLOP Consortium (Systematic and Combined Analysis of Olink Proteins). We summarize the cross-sectional epidemiological correlates of circulating ACE2. Using the summary statistics–based high-definition likelihood method, we estimate relevant genetic correlations with cardiometabolic phenotypes, COVID-19, and other human complex traits and diseases. We perform causal inference of soluble ACE2 on vascular disease outcomes and COVID-19 severity using mendelian randomization. We also perform in silico functional analysis by integrating with other types of omics data. Results: We identified 10 loci, including 8 novel, capturing 30% of the heritability of the protein. We detected that plasma ACE2 was genetically correlated with vascular diseases, severe COVID-19, and a wide range of human complex diseases and medications. An X-chromosome cis–protein quantitative trait loci–based mendelian randomization analysis suggested a causal effect of elevated ACE2 levels on COVID-19 severity (odds ratio, 1.63 [95% CI, 1.10–2.42]; P =0.01), hospitalization (odds ratio, 1.52 [95% CI, 1.05–2.21]; P =0.03), and infection (odds ratio, 1.60 [95% CI, 1.08–2.37]; P =0.02). Tissue- and cell type–specific transcriptomic and epigenomic analysis revealed that the ACE2 regulatory variants were enriched for DNA methylation sites in blood immune cells. Conclusions: Human plasma ACE2 shares a genetic basis with cardiovascular disease, COVID-19, and other related diseases. The genetic architecture of the ACE2 protein is mapped, providing a useful resource for further biological and clinical studies on this coronavirus receptor.

OBJECTIVES: Transaortic myectomy is a common procedure for patients with hypertrophic obstructive cardiomyopathy. Thoracoscopic trans-mitral myectomy has been described in a few small-sample studies and has been recommended as preferable. We herein report our clinical outcomes using the thoracoscopic trans-mitral approach with 76 patients. METHODS: This is a retrospective single-centre analysis of the safety and efficacy of thoracoscopic trans-mitral myectomy by comparing the clinical outcomes with that of transaortic myectomy. RESULTS: Between April 2019 and October 2021, 132 patients underwent either a transaortic (n = 56) or a thoracoscopic trans-mitral myectomy (n = 76). Compared with those in the transaortic group, patients in the trans-mitral group were more likely to be weaned off the ventilator within 24 h after surgery (80.3% vs 60.7%, P < 0.05) and to require a shorter duration of ventilation [29.01 (43.91) vs 51.12 (94.96) h, P = 0.08] and lower transfusion rate (26.3% vs 48.2%, P < 0.05). The in-hospital mortality rate of the transaortic and trans-mitral groups was 3.6% (n = 2) and 1.3% (n = 1), respectively. No significant inter-group differences were observed regarding in-hospital mortality, the incidence of low cardiac output syndrome or permanent pacemaker implantations. In the trans-mitral group, the thickness of the interventricular septum was significantly reduced postoperatively, with resultant relief of the left ventricular outflow tract obstruction [89.37 (27.5) vs 10.51 (0.65) mmHg, P < 0.01]. Transaortic myectomy also resulted in a significant reduction in left ventricular outflow tract gradient [90.41 (33.31) vs 11.35 (9.43) mmHg, P < 0.01]. And the incidence of residual systolic anterior motion of the trans-mitral group and the transaortic group was 2.67% and 1.9%, respectively. CONCLUSIONS: The thoracoscopic trans-mitral approach provides excellent exposure to the septum and anomalies of the mitral valve and papillary muscle. It relieves obstruction effectively, without increasing the incidence of major complications.

Objective: To demonstrate the technical details of total endoscopic aortic valve replacement using a standard prosthesis, compare the clinical effect and safety of endoscopic aortic valve replacement and traditional aortic valve replacement.Methods: From 2020 to 2021, 60 consecutive patients underwent elective isolated aortic valve replacement (AVR). They were divided into two groups: the total endoscopic AVR group (TE-AVR group, 29 patients, nine women, aged 51.65 ± 11.79 years), and the traditional full-sternotomy group (AVR group, 31 patients, 13 women, aged 54.23 ± 12.06 years). Three working ports were adopted in the TE-AVR procedure.Results: No patient died in either group. The cardiopulmonary bypass (CPB) time and aortic cross-clamp (ACC) time in the TE-AVR group were longer than those in the AVR group (CPB time: 177.6 ± 43.2 vs. 112.1 ± 18.1 min, p < 0.001; ACC time: 118.3 ± 29.7 vs. 67.0 ± 13.2 min, p < 0.001). However, the mechanical ventilation duration (14.2 ± 9.3 vs. 24.0 ± 18.9 h, p = 0.015) and postoperative hospital stay (6.0 ± 1.7 vs. 8.0 ± 4.5 days, p = 0.025) were shorter in patients of TE-AVR group than those of AVR group. Although the ICU stay (55.1 ± 26.9 vs. 61.5 ± 44.8 h, p = 0.509) and post-operative chest drainage of the first 24 h (229.8 ± 125.0 vs. 273.2 ± 103.2 ml, p = 0.146) revealed no statistical difference, there was a decreasing trend in the TE-AVR group. Among the patients of the TE-AVR group, two patients were converted to thoracotomy because of mild to moderate paravalvular leakage identified by intraoperative transesophageal echocardiography.Conclusion: Total endoscopic aortic valve replacement is safe and feasible, with less trauma and quicker recovery.

Pure aortic valve disease is common and has been treated with sternotomy aortic valve replacement for decades. Minimally invasive cardiac surgery has been widely used in atrioventricular valve lesions, but totally thoracoscopic aortic valve replacement has rarely been reported. The profiles of 9 patients who were diagnosed with severe aortic valve diseases and treated with two-port thoracoscopic aortic valve replacement between February 2021 and February 2022 were retrospectively reviewed. The clinical data, including baseline characteristics, operative data, postoperative complications, and short-term outcomes, were reported. All nine patients successfully underwent two-port thoracoscopic aortic valve replacement, with a cardiopulmonary bypass time of 137.56 ± 27.99 min and an aortic cross-clamp time of 95.33 ± 17.96 min. Seven (77.78%) patients underwent mechanical valve replacement, and two (22.22%) patients underwent bioprosthetic valve replacement. Two (22.22%) patients underwent a concomitant aortic root enlargement procedure. There were no intraoperative or postoperative deaths. The incidence of procedural complications was 0%, while the results of ventilation time, intensive care unit stay length, blood transfusion, chest tube drainage, and kidney function were satisfactory. Two-port thoracoscopic aortic valve replacement is a safe and effective surgical treatment option for carefully selected patients with pure aortic valve diseases.

Background: The thoracoscopic trans-mitral approach can not only facilitate exposure of the ventricular septum, mitral valve, and subvalvular apparatus, it also enables the surgeons to perform concomitant mitral valve intervention. This study aimed to determine the safety and efficacy of thoracoscopic trans-mitral septal myectomy in elderly patients with hypertrophic obstructive cardiomyopathy (HOCM).Methods: We reviewed the demographic to clinical characteristics and outcomes of patients who underwent thoracoscopic trans-mitral septal myectomy in our center between April 2019 and April 2021. The population was divided into a younger group (<60 years) and an elderly group (≥60 years).Results: There were 46 and 20 patients in the younger and elderly groups, respectively. The majority of patients in the elderly group were female (39.1 vs. 80.0%, P < 0.01). Patients in the elderly group were more likely to be in New York Heart Association Class IV (2.2 vs. 80.0%, P < 0.01). The European System for Cardiac Operation Risk Evaluation II predicted mortality rates were significantly higher (3.97 ± 1.81 vs. 1.62 ± 0.86%, P < 0.01) in the elderly group. In the elderly group, a patient converted to median sternotomy due to left ventricular posterior free wall rupture following septal myectomy and mitral bioprosthetic valve replacement. The patient then underwent double-patch sandwich repair for rupture and mitral mechanical valve replacement and was eventually discharged. All patients in the elderly group were discharged, while one in the younger group died. No patient in the elderly group required permanent pacemaker implantation vs. one in the younger group. Patients in the elderly group were more likely to spend more time in the intensive care unit than those in the younger group (5.44 ± 5.80 days vs. 3.07 ± 2.72, P < 0.05). However, there was no significant intergroup difference in in-hospital mortality or complications. Importantly, the left ventricular outflow tract pressure gradient was significantly decreased from 96.15 ± 32.89 mmHg to 8.2 ± 3.42 mmHg with no residual obstruction in the elderly group. The interventricular septal thickness was significantly decreased from 19.73 ± 3.14 mm to 11.30 ± 2.23 mm. Postoperative mitral regurgitation severity was significantly improved in the elderly group.Conclusion: This study demonstrated that thoracoscopic trans-mitral septal myectomy is a feasible option for selected elderly patients with satisfactory outcomes similar to those of young patients.

Background: This study aimed to summarize the perioperative and long-term outcomes of patients with previous mitral valve surgery (MVS) undergoing reoperative mitral valve replacement (MVR). Methods: Data for all reoperative mitral valve replacements (re-MVRs) with or without concomitant tricuspid surgery were analyzed from Guangdong Provincial People’s Hospital between January 2013 and December 2019. Propensity score matching resulted in 30 matched pairs with improved balance after matching in baseline covariates. Perioperative data and long‐term clinical outcomes were analyzed. Results: Results are based on the matched cohorts between the two groups. The in-hospital mortality was 3.3% (two deaths) in the entire cohort and was not significantly different between the median sternotomy (MS) group and the totally thoracoscopic (TT) group. Most patients in the TT group had their tracheal intubation removed within 24 hours of surgery. The TT group had a diminished requirement for blood transfusion and a reduced 4-day postoperative chest tube drainage amount. The incidence of early major complications, including all-cause death and reoperation due to bleeding, was lower in the TT group. No significant differences were observed in the 7-year survival probability between the two groups. Conclusions: The encouraging results regarding the perioperative and long-term outcomes of patients who underwent a TT re-MVR show that this approach is particularly beneficial for patients requiring reoperation.