The angiotensin converting enzyme (ACE) I/D polymorphism influences the plasmatic ACE levels, the highest being registered in the DD form. Similarly, the DD genotype is frequently associated with a CC homozygote genotype of the AT1 receptors. The polymorphism was studied mainly in hypertensive patients.
Objectives: To investigate the genetic polymorphism of renin angiotensin aldosterone system (RAAS) in patients with heart failure as a possible factor in determining the degree of the RAAS activation.
Methods: The study included 36 NYHA III and IV class heart failure patients, 20 males and 16 females, aged 71.03 +/- 9.52 years. The distribution of ACE gene insertion, deletion (I/D) and AT1 receptors Al166C gene polymorphism were determined. Analyses of ACE and AT1 receptors genotypes were performed by polymerase chain reaction (PCR).
Results: The distribution of genetic ACE polymorphism was: D/D-47.22% (17 p); I/D-22.22% (8 p); I/I-30.55% (11 p). The identified AT1 receptors genotypes were as follows: AA-50% (18 p); AC-41.66% (15 p), CC-8.33% (3p). The two types of genetic polymorphism were associated in both the 20 hypertensive patients: DD+AA-35% (7 p); DD+AC -25% (5 p); DD+CC-10% (2 p) and the 16 patients without hypertension: DD+AA-6.25% (lp); DD + AC-18.75% (3p). LEVF was < 40% in 10 patients, 40% of them presenting pathogenetic polymorphism (DD+AC or DD+CC.
Conclusion: Heart failure patients frequently present combinations of genetic polymorphism of RAAS probably involved in the development of neurohormonal pathogenic mechanism of the disease. This combination may be independent by the association with hypertension, and also in relationship with low ejection fraction.