Sun BJ, et al. J Cardiovasc Imaging. 2018 Dec;27:e19. https://doi.org/10.4250/jcvi.2019.27.e19

Background: Low 25-hydroxyvitamin D (25OHD) levels are common in patients with chronic heart failure (HF) and are associated with increased mortality risk. This study aimed to establish the safety and efficacy of oral vitamin D3 (cholecalciferol) supplementation and its effect on endothelial and ventricular function in patients with stable HF. Methods: This study was an investigator-initiated, multicenter, prospective, randomized, placebo-controlled trial. Seventy-three HF patients with 25OHD levels < 75 nmol/L (30 ng/mL) were randomized to receive 4000 IU vitamin D daily or a placebo for 6 months. The primary endpoint was a change in endothelial function between the baseline and after 6 months as assessed using EndoPAT. Secondary endpoints included changes in echocardiographic parameters and differences in quality of life (6-min walking test and New York Heart Association functional status) at 6 months. Results: There were no adverse events in either group during the study period. Vitamin D supplementation did not improve endothelial dysfunction (EndoPAT: baseline, 1.19 ± 0.4 vs 6 months later, 1.22 ± 0.3, P = .65). However, patients’ blood pressure, 6-min walking distance, and EQ-5D questionnaire scores improved after vitamin D treatment. In addition, a significant reduction in the left atrial diameter was observed. Conclusion: A daily vitamin D dose of 4000 IU for chronic HF appears to be safe. This dosage did not improve endothelial function but did improve the 6-min walk distance, symptoms, and left atrial diameter at 6 months.

Kim K, et al. J Cardiovasc Imaging. 2023 Jan;31:e12. https://doi.org/10.4250/jcvi.2022.0053

Amlodipine has a potential to reduce clopidogrel bioactivation through the cytochrome P450 3A4 enzyme in vivo, but the clinical impact of this interaction remains controversial. This randomized, open-label, two-period, crossover study was performed to evaluate the influence of amlodipine on the haemostatic profiles of high-risk patients during clopidogrel treatment. We recruited 40 Asian patients (Male/Female: n = 36/4) receiving clopidogrel (75 mg/day), aspirin (100 mg/day) and rosuvastatin for at least 6 months following percutaneous coronary intervention. Patients were randomly assigned to receive either 5 mg daily amlodipine or not for 2 weeks, and then were crossed over to the other treatment for 2 weeks. Haemostatic measurements were conducted with the VerifyNow assay and thromboelastography (TEG). Primary endpoint was P2Y12 Reaction Units (PRU) during on- versus off-amlodipine treatment. The on-amlodipine strategy showed higher level of PRU compared with the off-amlodipine strategy (176.8 ± 75.4 vs. 150.7 ± 65.5 PRU; ∆mean: 26.1 PRU; ∆95% confidence interval [CI]: 4.5–47.7 PRU; p = 0.019). Platelet-fibrin clot strength measured by TEG was lower during on- versus off-amlodipine treatment (7,712 ± 1,889 vs. 8,559 ± 2,174 dyne/cm²; ∆mean: –847 dyne/cm²; ∆95% CI: –1,632 to –62 dyne/cm²; p = 0.035). After amlodipine discontinuation, 27 patients (67.5%) showed a decrease in PRU, which was associated with ‘PRU ≥ 160 on-amlodipine’ in multivariate analysis (odds ratio: 62.014; 95% CI: 2.302–1670.328; p = 0.014). In conclusion, amlodipine increases platelet reactivity and decreases platelet-fibrin clot strength during clopidogrel treatment. In addition, the effect of amlodipine discontinuation on clopidogrel responsiveness is associated with on-amlodipine platelet reactivity. The authors are solely responsible for the design and conduct of this study, all study analyses, the drafting and editing of the manuscript and its final contents.