A study conducted recently has observed that the common drug used for treating high blood pressure and angina (chest pain) is associated with an increased risk of out-of-hospital sudden cardiac arrest.
Sudden cardiac arrest causes around half of the cardiac deaths in Europe and one in five natural deaths. The heart stops pumping after a cardiac arrhythmia (ventricular fibrillation/ tachycardia ); this can prove to be lethal in minutes if untreated. The results from the European Sudden Cardiac Arrest network (ESCAPE-NET) were presented today at EHRA 2019. It was set up to find the causes of arrhythmias so that it can be prevented. ESCAPE-NET is backed by the European Heart Rhythm Association (EHRA) of the European Society of Cardiology (ESC) and the European Resuscitation Council (ERC).
Dr Hanno Tan, ESCAPE-NET project leader and cardiologist, Academic Medical Centre, Amsterdam, Netherlands, urged caution when interpreting these results. He said, "The findings need to be replicated in other studies before action could be taken by doctors or patients."
The study examined if nifedipine and amlodipine, dihydropyridines widely used for high blood pressure and angina, are linked with out-of-hospital cardiac arrest. The nifedipine doses most often used and studied in this investigation are 30 mg and 60 mg (90 mg is available but infrequently used) and the amlodipine doses are 5 mg and 10 mg. Standard practice is to start with a lower dose, then give a higher dose if blood pressure or chest pain are not sufficiently reduced.
The analysis was done using data from the Dutch Amsterdam Resuscitation Studies registry (ARREST, 2005-2011) and confirmed in the Danish Cardiac Arrest Registry (DANCAR , 2001-2014), both part of ESCAPE-NET. Patients with out-of-hospital cardiac arrest due to ventricular fibrillation/tachycardia were enrolled, plus up to five controls per patient matched for age and sex. Controls were from the Dutch PHARMO Database Network and the general population in Denmark. In total, the study included 2,503 patients and 10,543 controls in the ARREST analysis and 8,101 patients and 40,505 controls in the DANCAR analysis.
Current use of high-dose (>60 mg/day), but not low-dose (<60 mg/day), nifedipine was significantly associated with an increased risk of out-of-hospital cardiac arrest compared to non-use of dihydropyridines, with an odds ratio of 1.5 in ARREST and 2.0 in DANCAR. High-dose nifedipine was also associated with an increased risk of out-of-hospital cardiac arrest when compared with any dose of amlodipine, with odds ratios of 2.3 and 2.2 in the ARREST and DANCAR registries, respectively. There was no risk associated with amlodipine.