Effect of Genetic Polymorphism on the Clinical Outcome of Patients With Heart Failure

Overview

Heart failure (HF) is one the most common cause of hospitalization and represents the end stage of a variety of heart conditions; it is associated with significant morbidity and mortality.The pathophysiology of HF is centered on increased activity in the adrenergic and renin-angiotensin-aldosterone systems (RAAS), which leads to vasoconstriction and fluid restriction with further deleterious effect on cardiac function. Β-blockers, angiotensin converting enzyme inhibitors (ACEIs)/angiotensin II receptor blockers (ARBs) and aldosterone antagonists reduce activity in these pathways and have shown prognostic benefit, thus are the foundation of HF therapy.There is a growing body of evidence that variation in proteins within the sympathetic axis and RAAS influence drug response thus increasingly pharmacogenetics of HF research is being sought as a way to optimize HF treatment and advance new drug development in this area.

In the past decade there has been considerable progress in cardiovascular pharmacogenetics and pharmacogenomics. Although drug response variation in Heart Failure is likely multifactorial, pharmacogenetic variation may partially account for therapeutic failure contributing to the remaining high mortality in HF. Identifying novel gene variants affecting treatment response may reveal unrecognized pathways and new potential therapeutic targets. Few studies to date have attempted to assess the extent to which variation in drug response was exclusively due to genetic factors and therefore expounding the likely clinical benefit of using pharmacogenetics to guide HF therapy. One of the prerequisites to bridging this gap is to consider likely trial designs and criteria that will lead to a consensus upon using pharmacogenetics-based variants to guide therapy in clinical practice. Another area gaining momentum is tailoring medication in response to biomarker levels as there is considerable evidence for the relationship between remodeling and fibrosis markers levels and worse prognosis in those with HF. Moreover,investigation into the proteomics of HF may also reveal variation that can be used to guide HF therapy hand-in-hand with biomarkers and pharmacogenomics, which would facilitate bridging the gap of genotype and phenotype. Disparity between genotype and phenotype may also account for the inconsistent results with current SNPs, further appreciation of this relationship would be a significant step forward.