Comprehensive biochemical analysis of rare prostacyclin receptor variants: study of association of signaling with coronary artery obstruction.

Currently, pharmacogenetic studies are at an impasse as the low prevalence (<2%) of most variants hinder their pharmacogenetic analysis with population sizes often inadequate for sufficiently powered studies. Grouping rare mutations by functional phenotype rather than mutation site can potentially increase sample size. Using human population-based studies (n = 1,761) to search for dysfunctional human prostacyclin receptor (hIP) variants, we recently discovered 18 non-synonymous mutations, all with frequencies less than 2% in our study cohort. Eight of the 18 had defects in binding, activation, and/or protein stability/folding. Mutations (M113T, L104R, and R279C) in three highly conserved positions demonstrated severe misfolding manifested by impaired binding and activation of cell surface receptors. To assess for association with coronary artery disease, we performed a case-control study comparing coronary angiographic results from patients with reduced cAMP production arising from the non-synonymous mutations (n = 23) with patients with non-synonymous mutations that had no reduction in cAMP (n = 17). Major coronary artery obstruction was significantly increased in the dysfunctional mutation group in comparison with the silent mutations. We then compared the 23 dysfunctional receptor patients with 69 age- and risk factor-matched controls (1:3). This verified the significantly increased coronary disease in the non-synonymous dysfunctional variant cohort. This study demonstrates the potential utility of in vitro functional characterization in predicting clinical phenotypes and represents the most comprehensive characterization of human prostacyclin receptor genetic variants to date.

Depression and cardiovascular disease.

Approximately one out of every five patients with cardiovascular disease (CVD) suffers from major depressive disorder (MDD). Both MDD and depressive symptoms are risk factors for CVD incidence, severity and outcomes. Great progress has been made in understanding potential mediators between MDD and CVD, particularly focusing on health behaviors. Investigators have also made considerable strides in the diagnosis and treatment of depression among patients with CVD. At the same time, many research questions remain. In what settings is depression screening most effective for patients with CVD? What is the optimal screening frequency? Which therapies are safe and effective? How can we better integrate the care of mental health conditions with that of CVD? How do we motivate depressed patients to change health behaviors? What technological tools can we use to improve care for depression? Gaining a more thorough understanding of the links between MDD and heart disease, and how best to diagnose and treat depression among these patients, has the potential to substantially reduce morbidity and mortality from CVD.

Accuracy and prognostic value of American Heart Association: recommended depression screening in patients with coronary heart disease: data from the Heart and Soul Study.

BACKGROUND- In 2008, the American Heart Association (AHA) recommended a 2-step screening method, consisting of the 2-item Patient Health Questionnaire (PHQ-2) followed by the 9-item Patient Health Questionnaire (PHQ-9), for identifying depression in cardiovascular patients. The accuracy and prognostic value of this screening method have not been evaluated. METHODS AND RESULTS- We administered the 2-step AHA-recommended screening algorithm to 1024 patients with stable coronary heart disease and calculated sensitivity and specificity against a gold standard interview for major depressive disorder. Subsequent cardiovascular events (myocardial infarction, stroke, transient ischemic attack, heart failure, or death) were determined during a mean of 6.27 ± 2.11 years of follow-up. The AHA-recommended screening method had high specificity (0.91; 95% confidence interval, 0.89 to 0.93) but low sensitivity (0.52; 95% confidence interval, 0.46 to 0.59) for a diagnosis of major depressive disorder. Participants who screened positive on the AHA depression protocol had a 55% greater risk of events than those who screened negative (age-adjusted hazard ratio, 1.55; 95% confidence interval, 1.21 to 1.97; P=0.0005). After adjustment for age, sex, body mass index, history of myocardial infarction, hypertension, diabetes, heart failure, and high-density lipoprotein levels, screening positive remained associated with a 41% greater rate of cardiovascular events (hazard ratio, 1.41; 95% confidence interval, 1.10 to 1.81; P=0.008). CONCLUSIONS- Among outpatients with stable coronary heart disease, the AHA-recommended depression screening protocol is highly specific for depression and identifies patients at risk for adverse cardiovascular outcomes.

The human prostacyclin receptor from structure function to disease.

Thirty years have passed since Vane and colleagues first described a substance, prostanoid X, from microsomal fractions (later called prostacyclin) that relaxed rather than contracted mesenteric arteries. The critical role of prostacyclin in many pathophysiological conditions, such as atherothrombosis, has only recently become appreciated (through receptor knockout mice studies, selective cyclooxygenase-2 inhibition clinical trials, and the discovery of dysfunctional prostacyclin receptor genetic variants). Additionally, important roles in such diverse areas as pain and inflammation, and parturition are being uncovered. Prostacyclin-based therapies, currently used for pulmonary hypertension, are accordingly emerging as possible treatments for such diseases, fueling interests in structure function studies for the receptor and signal transduction pathways in native cells. The coming decade is likely to yield many further exciting advances.