The bisoprolol efficiency predictors in patients with stable angina after myocardial infarction

Abstract

Objective: to identify the of bisoprolol effectiveness predictors in patients with stable angina after myocardial infarction.Materials and methods: 107 patients with stable angina who underwent myocardial infarction aged 35–65 years (mean age 54,7 ± 6,2 years) were examined in an open, comparative, register study, of which groups were generated: with the achieved and unreached target heart rate (60 or less in 1 minute). Additionally, the respondents were stratified into subsamples by the presence of ADRB1 gene Arg389Gly polymorphism. All patients underwent a 5-minute study of heart rate variability (HRV) in the background sample and in active orthostasis and the determination of the ADRB1 gene polymorphism (Arg389Gly, rs1801253) by PCR. All patients received bisoprolol in the selected optimal maximum-tolerated dose.The main results: respondents who did not reach the target heart rate significantly more often complained about heartbeat and heart rhythm interruptions (p = 0,003), increased incidence of cardiac pain episodes (p = 0,02), noted a high demand for nitrates (p = 0,03) and significantly more often sought medical help. In respondents with the achieved target heart rate, sympathetic influences were less expressed in the background HRV sample with significantly higher parasympathetic influences expression by contrast. The number of sympathicotonics in terms of HRV at rest was significantly higher among respondents with unreached heart rate. When comparing the frequencies of alleles in respondents with the achieved target heart rate, a significant (p = 0.0001) prevalence of carriers of the Gly allele of the ADRB1 gene Arg389Gly polymorphism was revealed. The heart rate in carriers of the Gly allele in homo-or heterozygous form was significantly lower than in carriers of the homozygous genotype Arg389Arg.Conclusion: The predictors of the bisoprolol effectiveness in achieving the target heart rate in patients with stable angina after MI are: a stress index less than 104.5 cu. in the background sample of a 5-minute HRV, the presence of the polymorphic Gly allele of the ADRB1 gene Arg389Gly polymorphism, the age of less than 46 years, and the total spectrum power in the background HRV sample of more than 1309 ms.