ABSTRACT
INTRODUCTION: Thrombocytopenia observed after bioprosthetic aortic valve replacement has remained a puzzle to solve. AIM: To analyze thrombocytopenia occurring after bioprosthetic aortic valve replacement by comparison to mechanical aortic valve replacement and coronary artery bypass grafting procedures. MATERIAL AND METHODS: The study was conducted retrospectively on a total of 297 patients who underwent bioprosthetic aortic valve replacement, mechanical prosthetic aortic valve replacement and coronary artery bypass grafting at the cardiovascular surgery department of our clinical center between January 2013 and September 2017. Preoperative and postoperative first 14-day thrombocyte levels of the patients were analyzed. RESULTS: The postoperative blood thrombocyte level decrease was found to be more significant in patients who underwent bioprosthetic aortic valve replacement than in patients who underwent mechanical aortic valve replacement and coronary artery bypass grafting (p < 0.01). There was also a statistically significant difference in the time to reach the lowest postoperative platelet levels according to type of surgery (p = 0.001; p < 0.01). CONCLUSIONS: When compared to the patients who underwent coronary artery bypass grafting and mechanical prosthetic aortic valve replacement, postoperative thrombocytopenia was found to be more severe in patients who underwent bioprosthetic aortic valve replacement, with a dramatic decrease in thrombocyte count being observed on the postoperative second day. It was found that the thrombocytopenia recovers without causing any problem. We think that the shear forces may play a role in this recovery through washout of chemicals responsible for thrombocytopenia from the glutaraldehyde treated bioprostheses.
ABSTRACT
INTRODUCTION: Oral anticoagulation with warfarin is indicated for patients with prosthetic heart valves. The effects of religious fasting during Ramadan month (in the Islamic calendar) on anticoagulation aren't clear. OBJECTIVES: To study the impact of Ramadan fasting on international normalized ratio (INR), quality of anticoagulation, dose of warfarin used and blood osmolarity. METHODS: 18 patients were followed-up prospectively for 3 months (pre- Ramadan, Ramadan and post-Ramadan months). Patients presented for weekly visits in which blood samples were obtained. RESULTS: No significant difference in INR and warfarin dose was found between Ramadan month, and months before and after it. The post-Ramadan INR was significantly larger than pre-Ramadan (p = 0.004). Blood osmolarity was significantly lower during Ramadan compared to pre- and post-Ramadan months. A significantly better quality of anticoagulation was noticed during Ramadan (p < 0.001). A significantly larger ratio of supratherapeutic INR values occurred in the post-Ramadan month (p < 0.05). A significantly larger ratio of infra-therapeutic INR values was noticed in the pre-Ramadan month (p < 0.05). CONCLUSION: No significant difference in mean INR or warfarin dose was found and a better quality of anticoagulation was achieved during Ramadan. A tendency toward supra-therapeutic anticoagulation occurred after Ramadan, thus a closer follow up during this period may be reasonable.
