The Importance of International Normalized Ratio Monitoring in Patients With Mechanical Pulmonary Valve Prosthesis.

Background: The most challenging risk of mechanical valves is thromboembolic events; therefore, life-long anticoagulation therapy is necessary. Anticoagulation therapy should be adjusted for each patient with serial international normalized ratio (INR) monitoring. Due to the small number of patients with a mechanical valve in the pulmonary position, we are facing a lack of information about the therapeutic range of the INR in these patients. We aimed to evaluate patients with a history of pulmonary valve replacement (PVR) who faced malfunction and compare their INR and echocardiographic data at the time of malfunction and 3 months prior. Methods: In this cross-sectional study, 71 patients who had previously undergone PVR and presented to Shaheed Rajaie Cardiovascular Medical and Research Center with a diagnosis of pulmonary valve malfunction between 2014 and 2021 were included. Patients' INR and echocardiographic data at the time of the malfunction and 3 months before the malfunction diagnosis were gathered from the hospital's registry. IBM SPSS 20.0 was used for data analysis. Results: In this cross-sectional study, 71 patients with mechanical pulmonary valve malfunction were included. 49.3% (n = 35) were men, 50.7% (n=36) were women, and their mean age was 33.23 (±8.279). The mean INR of all patients 3 months before malfunction and at the time of malfunction was 2.29 (±0.753) and 2.20 (±0.704), respectively. Conclusion: In this study, most of our patients had an INR below the therapeutic range, both at the time of malfunction and 3 months prior. It emphasizes the importance of patient follow-up and keeping the INR in the therapeutic range.

Mechanical tricuspid valve thrombosis: A midterm follow-up study.

BACKGROUND: The incidence of prosthetic tricuspid valve (TV) thrombosis is the highest among heart valves. It can lead to high morbidity and mortality without proper treatment. In this study, we sought to report the management and clinical outcomes of patients with mechanical TV thrombosis. METHODS: The current study was conducted in Rajaei Heart Center on 42 patients with mechanical TV thrombosis from 2006 to 2017. The baseline characteristics and the rates of adverse events during the follow-up period were assessed. RESULTS: A total of 67 episodes of mechanical TV thrombosis in 42 patients were observed. The mean age of patients was 45.5 ± 14.3 years (19-77), and overall two-thirds were female. Thrombolytic therapy was used in 41 (61.1%), anticoagulant intensification in 16 (23.9%), and surgery as the first approach in 10 (14.9%) episodes; subsequently, surgery as the final approach was implemented in 20 (29.8%) episodes. In-hospital mortality occurred in two (2.98%) patients. The rates of freedom from recurrent thrombosis were 84%, 61%, and 21% at the end of 1, 4, and 10 years, respectively. Survival rates and freedom from chronic valve dysfunction were 93%, 82%, and 75% after 1, 4, and 10 years. CONCLUSIONS: The results of the present study showed that recurrent thrombosis requiring intervention is a major complication of mechanical TV, which underscores individual-approached therapy and close follow-up.

Assessment of normal hemodynamic profile of mechanical pulmonary prosthesis by doppler echocardiography: a prospective cross-sectional study.

OBJECTIVES: Very few reports have described the Doppler-derived echocardiographic parameters for mechanical pulmonary valve prosthesis (MPVP). This study aims to describe the normal Doppler hemodynamic profile of MPVP using Doppler echocardiography. METHODS: The current prospective, single center observational study enrolled 108 patients who underwent pulmonary valve replacement (PVR) surgery for the first time and had a normally functioning prosthesis post-operation. The hemodynamic performance of MPVPs, considering flow dependent and flow independent parameters, was evaluated at two follow-up points, at week one and week four post-operation. All assessments were conducted by an experienced echocardiographer. RESULTS: The mean age (±SD) of the participants was 26.4 (±8.98). Tetralogy of Fallot (ToF) was the most common underlying disease leading to PVR, with a prevalence of 88%. At first week post-operation, measurement of indices reported the following values (±SD): peak pressure gradient (PPG): 18.51(±7.64) mm Hg; mean pressure gradient (MPG): 10.88(±5.62) mm Hg; peak velocity (PV): 1.97(±0.43)m/s; doppler velocity index (DVI): 0.61(±18); pulmonary velocity acceleration time (PVAT): 87.35(±15.16) ms; effective orifice area (EOA): 2.98(±1.02) cm2;and effective orifice area to body surface area ratio (EOA/ BSA): 1.81(±0.62) cm2/m2. Comparing these measurements with those obtained from the second follow-up (at week four post-op) failed to hold significant difference in all values except for PVAT, which had increased from its primary value (p = 0.038). Also, right ventricular (RV) function showed significant improvement throughout the follow up period. CONCLUSION: The findings of this study help strengthen the previously scarce data pool and better establish the normal values for Doppler hemodynamics in mechanical pulmonary prosthesis.

The effect of colchicine on the echocardiographic constrictive physiology after coronary artery bypass graft surgery.

BACKGROUND: Constrictive physiology is a transitory condition that could lead to constrictive pericarditis, which is a rare complication after open-heart surgery. Anti-inflammatory drugs like colchicine are recommended for prevention of constrictive pericarditis; however, there is no evidence about the effect of colchicine on constrictive pericarditis. Thus, the aim of this study is to evaluate the preventive effect of colchicine on the incidence of echocardiographic constrictive physiology after open-heart surgery. METHODS: This was a parallel randomized, double-blind trial. Patients were randomly assigned to receive 1 mg colchicine once-daily from 48 hours before and 0.5 mg twice daily for 5 days after surgery. Primary outcome was the incidence of the constrictive physiology after primary endpoint (1 week after the surgery). The secondary outcome was the primary outcome after secondary endpoint (4 weeks after surgery) plus the new cases of constrictive physiology between the primary and secondary endpoints. RESULTS: Out of 160 participating patients, the primary outcome occurred in 19 patients (23%) in placebo and 11 (13%) in intervention groups. There was no significant difference between two groups (P = .106). After 4 weeks of follow-up, 19 patients (23%) in placebo and 9 (11%) in intervention groups had constrictive physiology whereas 2 out of 11 patients (18.2%) were recovered. The difference was significant (P = .038). No new case of constrictive physiology occurred between primary and secondary endpoints. CONCLUSION: Short-term use of colchicine has a preventive effect on reducing constrictive physiology after 1 month of open-heart surgery but not a week after that.