Postcardiac surgery low cardiac output syndrome: dopexamine or dopamine?

Objective: To compare the efficacy and safety of dopexamine with dopamine in the treatment of low cardiac output syndrome after cardiac surgery. Design: This was a multicentre, double-blind, randomised, parallel-group study conducted in intensive care units at centres in Holland and Belgium. Patients were randomised to receive dopexamine (up to 2.0 μg/kg per min) or dopamine (up to 6.0 μg/kg per min) for 6 h after low cardiac output syndrome was confirmed. Results: 70 patients were enrolled (35/group) and there was no significant difference in the operative procedures or haemodynamics at entry into the study. Clinical efficacy, defined as a cardiac index > 2.5 l/min per m² with urine production > 0.5 ml/kg per h and stable haemodynamics for two consecutive readings 1 h apart, was achieved by 90 and 87 % of patients in the dopexamine and dopamine groups, respectively. However, more patients maintained clinical efficacy over the 6-h period in the dopexamine group, which was statistically significant at 1–2 h and approached significance at all other time points. Safety was assessed by comparing the adverse events and concomitant medication. Fewer patients on dopexamine had cardiac events compared with dopamine-treated patients (25 vs 38 events), although there was no difference in the pattern of rhythm disturbance. Fewer patients in the dopexamine group required concomitant vasodilating drugs (18 vs 30). Conclusion: Taking the proportion of patients achieving clinical efficacy, the time to achieve it and the maintenance of it along with the adverse event profile, dopexamine was shown to be an effective and safe drug to use in the management of low cardiac output syndrome after coronary artery bypass graft surgery and may be superior to dopamine. Received: 19 November 1996 Accepted: 8 July 1997     

Online Quantitative Aortographic Assessment of Aortic Regurgitation After TAVR: Results of the OVAL Study

ObjectivesThe aim of this study was to investigate the online assessment feasibility of aortography using videodensitometry in the catheterization laboratory during transcatheter aortic valve replacement (TAVR).BackgroundQuantitative assessment of regurgitation after TAVR through aortography using videodensitometry is simple, reproducible, and validated in vitro, in vivo, in clinical trials, and in “real-world” patients. However, thus far the assessment has been done offline.MethodsThis was a single center, prospective, proof-of-principle, feasibility study. One hundred consecutive patients with aortic stenosis and indications to undergo TAVR were enrolled. All final aortograms were analyzed immediately after acquisition in the catheterization laboratory and were also sent to an independent core laboratory for blinded offline assessment. The primary endpoint of the study was the feasibility of the online assessment of regurgitation (percentage of analyzable cases). The secondary endpoint was the reproducibility of results between the online assessment and the offline analysis by the core laboratory.ResultsPatients’ mean age was 81 ± 7 years, and 56% were men. The implanted valves were either SAPIEN 3 (97%) or SAPIEN 3 Ultra (3%). The primary endpoint of online feasibility of analysis was 92% (95% confidence interval [CI]: 86% to 97%) which was the same feasibility encountered by the core laboratory (92%; 95% CI: 86% to 97%). Reproducibility assessment showed a high correlation between online and core laboratory evaluations (R² = 0.87, p < 0.001), with an intraclass correlation coefficient of 0.962 (95% CI: 0.942 to 0.975; p < 0.001).ConclusionsThis study showed high feasibility of online quantitative assessment of regurgitation and high agreement between the online examiner and core laboratory. These results may pave the way for the application of videodensitometry in the catheterization laboratory after TAVR. (Online Videodensitometric Assessment of Aortic Regurgitation in the Cath-Lab [OVAL]; NCT04047082)     

The pharmacokinetics and pharmacodynamics of nifedipine at steady state during concomitant administration of cimetidine or high dose ranitidine.

Ranitidine may be used at doses of up to 300 mg twice daily in the healing of duodenal ulcers, and this study investigated the potential for a pharmacokinetic or pharmacodynamic interaction between nifedipine 10 mg three times daily and ranitidine 300 mg twice daily compared with cimetidine 800 mg daily and placebo in a randomised crossover study in 18 healthy male subjects. Twelve blood samples were taken on the fifth day in each treatment period and assayed for nifedipine by h.p.l.c. Pulse, blood pressure and ECG recordings were also taken. Cimetidine, but not ranitidine, produced significant changes in the pharmacokinetics of nifedipine at steady state. Mean +/- s.d. values of AUC were 105 +/- 40 micrograms l-1 for placebo treatment, 111 +/- 45 micrograms l-1 h for ranitidine and 211 +/- 64 micrograms l-1 h for cimetidine (P less than 0.001), and Cmax values were 33 +/- 14, 39 +/- 27 and 76 +/- 40 micrograms l-1 (P less than 0.001), respectively. Neither ranitidine nor cimetidine produced statistically significant changes in the pharmacological response to nifedipine.