Background: The response to angiotensin-I converting enzyme (ACE)-inhibitor therapy is highly variable. Residual ACE activity during treatment, potentially modified by the ACE insertion/deletion (I/D) polymorphism, may explain part of this variability. We studied the possible interaction between ACE-inhibitor therapy in patients with hypertension and the ACE I/D polymorphism in incident heart failure and death.
Methods: We studied 3365 hypertensive participants of the population-based Rotterdam Study, without heart failure at baseline for whom ACE-genotyping was successful. Incident heart failure was defined according to established criteria. In addition, total and cardiovascular mortality were studied as endpoints. A Cox regression model with use of ACE-inhibitors defined as time-dependent covariates was used for data-analysis. Interaction was tested in this model assuming an allele-effect relationship.
Results: Although we could not demonstrate a beneficial effect of ACE-inhibitors, there was significant interaction between the ACE I/D polymorphism (II-ID-DD) and ACE-inhibitor use in the prediction of total and cardiovascular mortality. Mortality risk associated with treatment increased with the number of D alleles present; e.g. for total mortality in the II genotype group: RR=0.95 (95% CI 0.63-1.45), in the ID genotype group: RR=1.08 (95% CI 0.84-1.38) and in the DD genotype group: RR=1.61 (95% CI 1.18-2.18). No statistically significant interaction was found for incident heart failure.
Conclusion: The results of our study suggest a relative resistance to ACE-inhibitor therapy in subjects with hypertension and the DD genotype compared to the II genotype, with the ID genotype in an intermediate position.