Thirty-year outcomes of low-intensity anticoagulation for mechanical aortic valve.

The long-term safety, efficacy, and outcomes of low-intensity anticoagulation for mechanical heart valves remain unclear. This study aimed to evaluate the long-term outcomes of low-intensity anticoagulation therapy after aortic valve replacement (AVR) with a mechanical prosthesis. This retrospective cohort study consulted medical records and conducted a questionnaire to investigate 519 patients who underwent single AVR with the St. Jude Medical bileaflet valve and were in sinus rhythm. All patients were followed up with an international normalized ratio (INR) target of 1.6-2.5, and their INR values were checked throughout the follow-up period. The survival rate, incidence of major adverse cardiac and cerebrovascular events (MACCE), and risk factors for cardiac death and MACCE were investigated. The total follow-up was 9793 patient-years, and the follow-up periods were 19.9 (standard deviation [SD]: 7.9) years. The mean INR was 2.03 (SD: 0.54). Survival rates from cardiac death were 93.6% in 20 years and 85.2% in 30 years. Advanced age ≥ 70 years was the only significant risk factor for cardiac death and MACCE, and the INR < 2.0 was not significant risk factor for MACCE including thromboembolism or bleeding events. Low-intensity anticoagulation with an INR of 1.6-2.5 for patients with sinus rhythm after AVR with a bileaflet mechanical valve is safe and effective, even over 30 years.

Acquired left ventricular-right atrial communication after mitral valve replacement and tricuspid annuloplasty.

A 77-year-old woman underwent mitral valve replacement and tricuspid annuloplasty for severe mitral stenosis and tricuspid regurgitation with pulmonary hypertension. Two months later, the patient was readmitted because of marked edema. A new harsh pansystolic murmur was auscultated, and echocardiography revealed a jet from the left ventricle to the right atrium but no paravalvular leakage was detected at the mitral valve position. At operation, an 6 mm defect adjacent to the tricuspid annulus in the interatrial septum and detachment of the anterior edge of the tricuspid ring were detected. The defect was closed using a pericardial patch. An inadequate stitch at the anteroseptal commissure in the previous operation led to left ventricular-right atrial communication.

Regional oxygen saturation change rate for detection of leg ischemia in minimally invasive cardiac surgery.

INTRODUCTION: The criteria for placement of distal perfusion cannulas vary among reports. This cohort study aimed to establish a reproducible method to monitor critical leg ischemia during minimally invasive cardiac surgery. METHODS: We included 121 patients who underwent minimally invasive cardiac surgery via right thoracotomy with right femoral arterial cannulation from 2015 to 2018. The change rate of regional oxygen saturation (ΔrSO2) was calculated as follows: rSO2 (baseline) - rSO2 (actual number)/rSO2 (baseline). Patients were divided into Group N (ΔrSO2 < 40%): 100/121 (83%) and Group H (ΔrSO2 > 40%, <10 minutes if >40%): 21/121 (17%). A distal perfusion cannula was placed when ΔrSO2 was >40% over 10 minutes. RESULTS: No patients experienced significant leg ischemia. Significantly longer cardiopulmonary bypass and aortic cross-clamp times were observed in Group H than in Group N (cardiopulmonary bypass time, 129 ± 36 minutes (Group N) vs. 151 ± 34 minutes (Group H), p = 0.01). ΔrSO2 correlated positively with plasma creatine phosphokinase elevation (R = 0.40, p < 0.001) on postoperative day 1. Serum lactate on intensive care unit admission showed a significant positive correlation (R = 0.40, p < 0.001) with ΔrSO2. CONCLUSION: ΔrSO2 measurement by near-infrared spectroscopy can facilitate distal leg perfusion monitoring and assist surgeons in preventing critical leg ischemia during minimally invasive cardiac surgery.

The learning curve of minimally invasive aortic valve replacement for aortic valve stenosis.

OBJECTIVE: Few clinical studies have been conducted to evaluate the learning curve of minimally invasive aortic valve replacement. The purpose of this study was to retrospectively analyze the learning curve of initial and isolated minimally invasive aortic valve replacement for aortic valve stenosis which performed at our institution. METHODS: This study included 126 patients who underwent initial and isolated minimally invasive aortic valve replacement via right infra-axillary mini thoracotomy for aortic valve stenosis. Patients were divided into the first 50 patients [1-50 cases: E group (n = 50)] and the last 76 patients [51-126 cases: L group (n = 76)]. RESULTS: A significantly shorter operative time (239.4 ± 35.2 min vs. 206.5 ± 25.5 min, P < 0.001), cardiopulmonary bypass time (151.1 ± 27.4 min vs. 126.9 ± 20.2 min, P < 0.001) and aortic cross-clamp time (115.2 ± 19.0 min vs. 93.9 ± 14.7 min, P < 0.001) were found in the L group. The learning curves of operative time, cardiopulmonary bypass time, and aortic cross-clamp time plateaued after 40 cases. CONCLUSIONS: Learning curves were observed in surgical processes such as operative time. A total of 40-50 cases are required to achieve a stable operative time. However, patient outcomes were not significantly different between the groups. This study could be helpful in introducing minimally invasive aortic valve replacement and designing training programs.