Infective endocarditis.

First described more than 350 years ago, infective endocarditis represents a global health concern characterised by infections affecting the native or prosthetic heart valves, the mural endocardium, a septal defect, or an indwelling cardiac device. Over recent decades, shifts in causation and epidemiology have been observed. Echocardiography remains pivotal in the diagnosis of infective endocarditis, with alternative imaging modalities gaining significance. Multidisciplinary management requiring expertise of cardiologists, cardiovascular surgeons, infectious disease specialists, microbiologists, radiologists and neurologists, is imperative. Current recommendations for clinical management often rely on observational studies, given the limited number of well conducted randomised controlled trials studying infective endocarditis due to the rarity of the disease. In this Seminar, we provide a comprehensive overview of optimal clinical practices in infective endocarditis, highlighting key aspects of pathophysiology, pathogens, diagnosis, management, prevention, and multidisciplinary approaches, providing updates on recent research findings and addressing remaining controversies in diagnostic accuracy, prevention strategies, and optimal treatment.

Long-Term Safety, Tolerability and Survival in Patients with Pulmonary Arterial Hypertension Treated with Macitentan: Results from the SERAPHIN Open-Label Extension.

INTRODUCTION: In SERAPHIN, a long-term, event-driven, double-blind randomised controlled trial in pulmonary arterial hypertension (PAH), macitentan 10 mg significantly reduced the risk of morbidity/mortality compared with placebo. Its open-label extension study (SERAPHIN OL) further assessed long-term safety and tolerability of macitentan 10 mg in PAH patients. METHODS: Patients in SERAPHIN who completed the double-blind treatment period or experienced a morbidity event during the study could enter SERAPHIN OL. Patients received macitentan 10 mg once daily, and safety and survival were assessed until end of treatment (+ 28 days). Two overlapping sets were analysed for safety: (1) all patients in SERAPHIN OL (OL safety set); (2) patients randomised to macitentan 10 mg in SERAPHIN (long-term safety/survival set). Survival was evaluated as an exploratory endpoint in the latter set. RESULTS: Of 742 patients randomised in SERAPHIN, 550 (74.1%) entered SERAPHIN OL (OL safety set); 242 patients were randomised to macitentan 10 mg in SERAPHIN (long-term safety/survival set). Median (min, max) exposure to macitentan 10 mg was 40.1 (0.1, 130.5) months (2074.7 patient-years; OL safety set) and 54.7 (0.1, 141.3) months (1151.0 patient-years; long-term safety/survival set). Safety in both analysis sets was comparable to the known safety profile of macitentan. Kaplan-Meier survival estimates (95% CI) at 1, 5, 7 and 9 years were 95.0% (91.3, 97.1), 73.3% (66.6, 78.9), 62.6% (54.6, 69.6) and 52.7% (43.6, 61.0), respectively (long-term safety/survival set; median follow-up: 5.9 years). CONCLUSIONS: This analysis provides the longest follow-up for safety and survival published to date for any PAH therapy. The safety profile of macitentan 10 mg over this extensive treatment period was in line with that observed in SERAPHIN. As the majority of patients were receiving other PAH therapy at macitentan initiation, our study provides additional insight into the long-term safety of macitentan, including as part of combination therapy. TRIAL REGISTRATION: ClinicalTrials.gov Identifiers: NCT00660179 and NCT00667823.

Current status and barriers in pulmonary hypertension care delivery in India: A qualitative analysis.

Although pulmonary hypertension (PH) is widely prevalent in India, care delivery for this condition has unique challenges in a lower middle-income country (LMIC). To describe care delivery for patients with PH and associated barriers in India. We interviewed physicians across eight healthcare systems in India about PH clinical care using semi-structured enquiries to understand care delivery and associated challenges in their specific practice as well as the associated health system. Qualitative analysis was performed using content analysis methodology. Physicians reported that common causes for PH in their practice were rheumatic mitral valve disease, coronary artery disease, and congenital heart disease (CHD). No center had a dedicated PH program. Only one center had a specific protocol for PH management. Diagnostic evaluations were limited, and right heart catheterizations were recommended for patients with CHD. Pulmonary vasodilator therapy was used for severe symptoms or markers of severe disease. Agents used to treat PH were widely variable across physicians and prostacyclins are unavailable in India. Barriers included limited training in PH for physicians, lack of consensus guidelines for PH specific to LMIC, and lack of financial incentives for health care systems to organize dedicated PH programs. Other barriers included poor patient health literacy and socioeconomic barriers that limit ability to test and treat PH. PH care delivery in India is variable with widely differing clinical practices. Dedicated training in PH management and establishing guidelines specific to LMIC like India can form the first step forward.

Integrating Data From Randomized Controlled Trials and Observational Studies to Assess Survival in Rare Diseases.

Background Conducting randomized controlled trials to investigate survival in a rare disease like pulmonary arterial hypertension has considerable ethical and logistical constraints. In many studies, such as the Study with an Endothelin Receptor Antagonist in Pulmonary Arterial Hypertension to Improve Clinical Outcome (SERAPHIN) randomized controlled trial, evaluating survival is further complicated by bias introduced by allowing active therapy among placebo-treated patients who clinically deteriorate. Methods and Results SERAPHIN enrolled and followed patients in the same time frame as the US Registry to Evaluate Early And Long-term PAH Disease Management, providing an opportunity to compare observed survival for SERAPHIN patients with predicted survival had they received real-world treatment as in the Registry to Evaluate Early And Long-term PAH Disease Management. From the Registry to Evaluate Early And Long-term PAH Disease Management (N=3515), 734 patients who met SERAPHIN eligibility criteria were selected and their data used to build a prediction model for time to death up to 3 years based on 10 baseline prognostic variables. The model was used to predict a survival curve for each of the 742 SERAPHIN patients via their baseline variables. The average of these predicted survival curves was compared with observed survival of the placebo (n=250) and macitentan 10 mg (n=242) groups using a log-rank test and Cox proportional hazard model. Observed mortality risk for patients randomized to placebo, 62% of whom were taking background pulmonary arterial hypertension therapy, tended to be lower than that predicted for all SERAPHIN patients (16% lower; P=0.259). The observed placebo survival curve closely approximated the predicted survival curve for the first 15 months. Beyond that time, observed risk of mortality decreased compared with predicted mortality, potentially reflecting the impact of crossover of patients in the placebo group to active therapy. Over 3 years, risk of mortality observed with macitentan 10 mg was 35% lower than predicted mortality ( P=0.010). Conclusions These analyses show that, in a rare disease, real-world observational data can complement randomized controlled trial data to overcome some challenges associated with assessing survival in the setting of a randomized controlled trial. Clinical Trial Registration https://www.clinicaltrials.gov . Unique identifiers: NCT00660179 and NCT00370214.

One-year clinical outcomes of different coronary drug eluting stents-Data from a prospective registry.

We compared one-year clinical outcomes of different drug eluting stents (DES) used in a prospective observation registry maintained in two hospitals over three years. The primary endpoint was combination of all-cause mortality, stent thrombosis and revascularization. There was no significant difference among different DES. We grouped DES into well-evaluated Imported DES (Imported group), which used to be expensive prior to price control and economical Indian DES (Indigenous group) that lack supportive clinical trials. One-year follow-up data was available in 99% of Indigenous group (n=1856) and 98.5% of Imported group (n=1539). After propensity score matching, there were 1310 matched pairs. There was no significant difference between two groups in the primary end-point or each of the components.

Association between six-minute walk distance and long-term outcomes in patients with pulmonary arterial hypertension: Data from the randomized SERAPHIN trial.

BACKGROUND: Patients with pulmonary arterial hypertension who achieve a six-minute walk distance of 380-440 m may have improved prognosis. Using the randomized controlled trial of macitentan in pulmonary arterial hypertension (SERAPHIN), the association between six-minute walk distance and long-term outcomes was explored. METHODS: Patients with six-minute walk distance data at Month 6 were dichotomized as above or below the median six-minute walk distance (400 m) and assessed for future risk of pulmonary arterial hypertension-related death or hospitalization and all-cause death. Additionally, six-minute walk distance values at baseline, Month 6 and the change from baseline to Month 6 were categorized by quartiles. All associations were analyzed by the Kaplan-Meier method using a log-rank test and Cox regression models. RESULTS: Patients with a six-minute walk distance >400 m vs. ≤400 m at Month 6 have a reduced risk of pulmonary arterial hypertension-related death or hospitalization (hazard ratio 0.48; 95% confidence interval 0.33-0.69). The risk was also lower for patients with higher quartiles of six-minute walk distance at baseline or Month 6 (baseline: hazard ratio [Q4 (>430 m) vs. Q1 (≤300 m)] 0.23; 95% confidence interval 0.15-0.36; Month 6: hazard ratio [Q4 (>455 m) vs. Q1 (≤348 m)] 0.33; 95% confidence interval 0.19-0.55). In contrast, six-minute walk distance changes at Month 6 were not associated with the risk of pulmonary arterial hypertension-related death or hospitalization (p = 0.477). These findings were consistent when adjusted for known confounders. Similar results were observed for the risk of all-cause death up to end of study. CONCLUSIONS: Patients with pulmonary arterial hypertension walking >400 m had better long-term prognosis. Although changes in six-minute walk distance were not associated with long-term outcomes, assessing absolute six-minute walk distance values remains important in the clinical management of patients with pulmonary arterial hypertension.

Pulmonary Arterial Hypertension-Related Morbidity Is Prognostic for Mortality.

BACKGROUND: Registry data suggest that disease progression in pulmonary arterial hypertension (PAH) is indicative of poor prognosis. However, the prognostic relevance of PAH-related morbidity has not been formally evaluated in randomized controlled trials. OBJECTIVES: The purpose of these analyses was to assess the impact of morbidity events on the risk of subsequent mortality using the landmark method and data from the SERAPHIN and GRIPHON studies. METHODS: For each study, the risk of all-cause death up to the end of the study was assessed from the landmark time point (months 3, 6, and 12) according to whether a patient had experienced a primary endpoint morbidity event before the landmark. Each analysis was conducted using data from all patients who were available for survival follow-up at the landmark. RESULTS: In the SERAPHIN study, on the basis of the 3-month landmark time point, patients who experienced a morbidity event before month 3 had an increased risk of death compared with patients who did not (hazard ratio [HR]: 3.39; 95% confidence interval [CI]: 1.94 to 5.92). In the GRIPHON study, on the basis of the 3-month landmark time point, there was also an increased risk with a HR of 4.48; (95% CI: 2.98 to 6.73). Analyses based on 6-month and 12-month landmarks also showed increased risk in patients who experienced morbidity events, albeit with a reduced HR. CONCLUSIONS: These results demonstrate the prognostic relevance of PAH-related morbidity as defined in the SERAPHIN and GRIPHON studies, highlighting the importance of preventing disease progression in patients with PAH and supporting the clinical relevance of SERAPHIN and GRIPHON morbidity events. (Study of Macitentan [ACT-064992] on Morbidity and Mortality in Patients With Symptomatic Pulmonary Arterial Hypertension [SERAPHIN]; NCT00660179; Selexipag [ACT-293987] in Pulmonary Arterial Hypertension [GRIPHON]; NCT01106014).

Mitochondria-targeted esculetin inhibits PAI-1 levels by modulating STAT3 activation and miR-19b via SIRT3: Role in acute coronary artery syndrome.

In this study we explored the microRNAs responsible for the regulation of PAI-1 during LPS-stimulated inflammation in human aortic endothelial cells and subsequently studied the effect of a newly synthesized mitochondria-targeted esculetin (Mito-Esc) that was shown for its anti-atherosclerotic potential, in modulating PAI-1 levels and its targeted miRs during angiotensin-II-induced atherosclerosis in ApoE-/- mice. LPS-stimulated PAI-1 was accompanied with an upregulation of miR-19b and down-regulation of miR-30c. These effects of LPS on PAI-1 were reversed in the presence of both parent esculetin and Mito-Esc. However, the effect of Mito-Esc was more pronounced in the regulation of PAI-1. In addition, LPS-stimulated PAI-1 expression was significantly decreased in cells treated with Anti-miR-19b, thereby suggesting that miR-19b co-expression plays a key role in PAI-1 regulation. The results also show that incubation of cells with Stattic, an inhibitor of STAT-3, inhibited LPS-stimulated PAI-1 expression. Interestingly, knockdown of SIRT3, a mitochondrial biogenetic marker, enhanced PAI-1 levels via modulation of miR-19b and -30c. Mito-Esc treatment significantly inhibited Ang-II-induced PAI-1, possibly via altering miR-19b and 30c in ApoE-/- mice. The association between PAI-1, miR-19b and -30c were further confirmed in plasma and microparticles isolated from patients suffering from acute coronary syndrome of various degrees. Taken together, LPS-induced PAI-1 involves co-expression of miR-19b and down regulation of miR-30c, and Mito-Esc treatment by modulating miR-19b and miR-30c through SIRT3 activation, inhibits PAI-1 levels that, in part, contribute to its anti-atherosclerotic effects. Moreover, there exists a strong positive correlation between miR-19b and PAI-1 in patients suffering from ST-elevated myocardial infarction.

SERAPHIN haemodynamic substudy: the effect of the dual endothelin receptor antagonist macitentan on haemodynamic parameters and NT-proBNP levels and their association with disease progression in patients with pulmonary arterial hypertension.

Aims: The effect of macitentan on haemodynamic parameters and NT-proBNP levels was evaluated in pulmonary arterial hypertension (PAH) patients in the SERAPHIN study. Association between these parameters and disease progression, assessed by the primary endpoint (time to first morbidity/mortality event), was explored. Methods and results: Of the 742 randomized patients, 187 with right heart catheterization at baseline and month 6 participated in a haemodynamic sub-study. Prespecified endpoints included change from baseline to month 6 in cardiac index (CI), right atrial pressure (RAP), mean pulmonary arterial pressure (mPAP), pulmonary vascular resistance (PVR), mixed-venous oxygen saturation, and NT-proBNP. Exploratory analyses examined associations between CI, RAP, and NT-proBNP and disease progression using the Kaplan-Meier method and Cox regression models. Macitentan improved CI, RAP, mPAP, PVR and NT-proBNP vs. placebo at month 6. Absolute levels of CI, RAP and NT-proBNP at baseline and month 6, but not their changes, were associated with morbidity/mortality events. Patients with CI > 2.5 L/min/m2, RAP < 8 mmHg, or NT-proBNP < 750 fmol/ml at month 6 had a lower risk of morbidity/mortality than those not meeting these thresholds (HR 0.49, 95% CL 0.28-0.86; HR 0.72, 95% CL 0.42-1.22; and HR 0.22, 95% CL 0.15-0.33, respectively). Conclusions: For all treatment groups, baseline and month 6 values of CI, RAP, and NT-proBNP, but not their changes, were associated with morbidity/mortality events, confirming their relevance in predicting disease progression in patients with PAH. By improving those parameters, macitentan increased the likelihood of reaching threshold values associated with lower risk of morbidity/mortality.

Efficacy of 1, 5, and 20 mg oral sildenafil in the treatment of adults with pulmonary arterial hypertension: a randomized, double-blind study with open-label extension.

BACKGROUND: In a previous study, 6-minute walk distance (6MWD) improvement with sildenafil was not dose dependent at the 3 doses tested (20, 40, and 80 mg 3 times daily [TID]). This study assessed whether lower doses were less effective than the approved 20-mg TID dosage. METHODS: Treatment-naive patients with pulmonary arterial hypertension were randomized to 12 weeks of double-blind sildenafil 1, 5, or 20 mg TID; 12 weeks of open-label sildenafil 20 mg TID followed. Changes from baseline in 6-minute walk distance (6MWD) for sildenafil 1 or 5 mg versus 20 mg TID were compared using a Williams test. Hemodynamics, functional class, and biomarkers were assessed. RESULTS: The study was prematurely terminated for non-safety reasons, with 129 of 219 planned patients treated. At week 12, 6MWD change from baseline was significantly greater for sildenafil 20 versus 1 mg (P = 0.011) but not versus 5 mg. At week 24, 6MWD increases from baseline were larger in those initially randomized to 20 versus 5 or 1 mg (74 vs 50 and 47 m, respectively). At week 12, changes in hemodynamic parameters were generally small and variable between treatment groups; odds ratios for improvement in functional class were not statistically significantly different. Improvements in B-type natriuretic peptide levels were significantly greater with sildenafil 20 versus 1 but not 5 mg. CONCLUSIONS: Sildenafil 20 mg TID appeared to be more effective than 1 mg TID for improving 6MWD; sildenafil 5 mg TID appeared to have similar clinical and hemodynamic effects as 20 mg TID. TRIAL REGISTRATION: ClinicalTrials.gov NCT00430716 (Registration date: January 31, 2007).

Incident and prevalent cohorts with pulmonary arterial hypertension: insight from SERAPHIN.

In SERAPHIN, a long-term, randomised, controlled trial (NCT00660179) in pulmonary arterial hypertension (PAH), macitentan significantly reduced the risk of morbidity/mortality and PAH-related death/hospitalisation. We evaluated disease progression and the effect of macitentan in treatment-naïve incident and prevalent cohorts.Patients allocated to placebo, or macitentan 3 mg or 10 mg were classified by time from diagnosis to enrolment as incident (≤6 months; n=110) or prevalent (>6 months; n=157). The risk of morbidity/mortality and PAH-related death/hospitalisation was determined using Cox regression.The risk of morbidity/mortality (Kaplan-Meier estimates at month 12: 54.4% versus 26.7%; p=0.006) and PAH-related death/hospitalisation (Kaplan-Meier estimates at month 12: 47.3% versus 19.9%; p=0.006) were significantly higher for incident versus prevalent patients receiving placebo, respectively. There was no significant difference in the risk of all-cause death between incident and prevalent cohorts (p=0.587). Macitentan 10 mg significantly reduced the risk of morbidity/mortality and PAH-related death/hospitalisation versus placebo in incident and prevalent cohorts.Incident patients had a higher risk for PAH progression compared with prevalent patients but not a higher risk of death. Macitentan delayed disease progression in both incident and prevalent PAH patients.

Effect of macitentan on hospitalizations: results from the SERAPHIN trial.

OBJECTIVES: This study sought to evaluate the effect of macitentan on hospitalization of patients with symptomatic pulmonary arterial hypertension (PAH). BACKGROUND: PAH is a progressive, life-threatening disease often requiring hospitalization. METHODS: In the multicenter, double-blind, randomized, event-driven, phase III SERAPHIN (Study with an Endothelin Receptor Antagonist in Pulmonary arterial Hypertension to Improve cliNical outcome) trial, patients with symptomatic PAH were randomized (1:1:1) to receive placebo or 3 mg or 10 mg of macitentan. Effects of macitentan on the risk, rate, and number of hospital days for all-cause and PAH-related hospitalizations were compared with those for placebo. Risk and causes of hospitalizations unrelated to PAH were investigated. RESULTS: Of 742 randomized patients, 250 received placebo, 250 received 3 mg of macitentan, and 242 received 10 mg of macitentan; the overall median duration of treatment was 115 weeks. Risk of all-cause hospitalization was reduced by 18.9% (p = 0.1208) and 32.3% (p = 0.0051) in the macitentan 3-mg and 10-mg arm, respectively. Rates of all-cause hospitalizations and numbers of hospital days were reduced by 20.5% (p = 0.0378) and 30.6% (p = 0.0278), respectively, with 3 mg of macitentan and by 33.1% (p = 0.0005) and 31.0% (p = 0.0336), respectively, with 10 mg of macitentan. Risk of PAH-related hospitalizations were reduced by 42.7% (p = 0.0015) and 51.6% (p < 0.0001) in the macitentan 3-mg and 10-mg arms, respectively. Rate of PAH-related hospitalizations and numbers of hospital days were reduced by 44.5% (p = 0.0004) and 53.3% (p = 0.0001), respectively, with 3 mg of macitentan, and reduced by 49.8% (p < 0.0001) and 52.3% (p = 0.0003), respectively, with 10 mg of macitentan. Risk of non-PAH-related hospitalization was similar between treatment arms. CONCLUSIONS: Macitentan 10 mg significantly reduced the risk and rate of all-cause hospitalization, which was driven by reductions in the risk and rate of PAH-related hospitalization. (Study of Macitentan [ACT-064992] on Morbidity and Mortality in Patients With Symptomatic Pulmonary Arterial Hypertension; NCT00660179).

Real world experience with an indigenously manufactured stent Cobal C--a retrospective study.

BACKGROUND: Second generation bare metal stents made of cobalt chromium alloy are superior to first generation stain less steel stents. The thin struts are shown to reduce clinical and angiographic adverse outcomes. OBJECTIVE: To study the long term clinical and angiographic outcomes in patients who underwent coronary angioplasty with an indigenously made cobalt chromium bare metal stents with thin strut Cobal+C™ (Relisys). METHODS: A total of 268 consecutive patients who underwent coronary angioplasty with Cobal+C stents were studied retrospectively. Clinical follow up was done after a minimum period of nine months through telephonic interview and angiographic follow up was done in 80 patients chosen randomly. The end points analyzed included major adverse cardiac events (MACE) at nine months and the rate of binary restenosis at follow up angiogram done between 9 and 15 months post angioplasty. RESULTS: Thirty four percent were diabetic and 33% had acute myocardial infarction. Females constituted 17%. Mean stent diameter was 2.88 ± 0.28 and mean stent length 18.8 ± 4.2. MACE at nine months was 4.5% with TLR 0.3%. The rate of binary restenosis was 21%. Patients with longer stent lengths and non-compliance with medications had significantly higher rates of binary restenosis. CONCLUSIONS: The use of Relisys Cobal+C stents was associated with good long term clinical and angiographic outcomes as evidenced by low incidence of MACE and binary restenosis rates for a bare metal stent.

Regression of pulmonary artery hypertension due to development of a pulmonary arteriovenous malformation.

Idiopathic Pulmonary Hypertension (IPAH) is characterized by elevated pulmonary arterial pressure in the absence of an identifiable underlying cause. The condition is usually relentlessly progressive with a short survival in the absence of treatment.(1) We describe a patient of IPAH in whom the pulmonary artery pressures significantly abated with complete disappearance of symptoms, following spontaneous development of a pulmonary arterio-venous malformation (PAVM).

Macitentan and morbidity and mortality in pulmonary arterial hypertension.

BACKGROUND: Current therapies for pulmonary arterial hypertension have been adopted on the basis of short-term trials with exercise capacity as the primary end point. We assessed the efficacy of macitentan, a new dual endothelin-receptor antagonist, using a primary end point of morbidity and mortality in a long-term trial. METHODS: We randomly assigned patients with symptomatic pulmonary arterial hypertension to receive placebo once daily, macitentan at a once-daily dose of 3 mg, or macitentan at a once-daily dose of 10 mg. Stable use of oral or inhaled therapy for pulmonary arterial hypertension, other than endothelin-receptor antagonists, was allowed at study entry. The primary end point was the time from the initiation of treatment to the first occurrence of a composite end point of death, atrial septostomy, lung transplantation, initiation of treatment with intravenous or subcutaneous prostanoids, or worsening of pulmonary arterial hypertension. RESULTS: A total of 250 patients were randomly assigned to placebo, 250 to the 3-mg macitentan dose, and 242 to the 10-mg macitentan dose. The primary end point occurred in 46.4%, 38.0%, and 31.4% of the patients in these groups, respectively. The hazard ratio for the 3-mg macitentan dose as compared with placebo was 0.70 (97.5% confidence interval [CI], 0.52 to 0.96; P=0.01), and the hazard ratio for the 10-mg macitentan dose as compared with placebo was 0.55 (97.5% CI, 0.39 to 0.76; P<0.001). Worsening of pulmonary arterial hypertension was the most frequent primary end-point event. The effect of macitentan on this end point was observed regardless of whether the patient was receiving therapy for pulmonary arterial hypertension at baseline. Adverse events more frequently associated with macitentan than with placebo were headache, nasopharyngitis, and anemia. CONCLUSIONS: Macitentan significantly reduced morbidity and mortality among patients with pulmonary arterial hypertension in this event-driven study. (Funded by Actelion Pharmaceuticals; SERAPHIN ClinicalTrials.gov number, NCT00660179.).

Epistatic interactions in idiopathic pulmonary arterial hypertension.

BACKGROUND: Idiopathic pulmonary arterial hypertension (IPAH) is a poorly understood complex disorder, which results in progressive remodeling of the pulmonary artery that ultimately leads to right ventricular failure. A two-hit hypothesis has been implicated in pathogenesis of IPAH, according to which the vascular abnormalities characteristic of PAH are triggered by the accumulation of genetic and/or environmental insults in an already existing genetic background. The multifactor dimensionality reduction (MDR) analysis is a statistical method used to identify gene-gene interaction or epistasis and gene-environment interactions that are associated with a particular disease. The MDR method collapses high-dimensional genetic data into a single dimension, thus permitting interactions to be detected in relatively small sample sizes. AIM: To identify and characterize polymorphisms/genes that increases the susceptibility to IPAH using MDR analysis. MATERIALS AND METHODS: A total of 77 IPAH patients and 100 controls were genotyped for eight polymorphisms of five genes (5HTT, EDN1, NOS3, ALK-1, and PPAR-γ2). MDR method was adopted to determine gene-gene interactions that increase the risk of IPAH. RESULTS: With MDR method, the single-locus model of 5HTT (L/S) polymorphism and the combination of 5HTT(L/S), EDN1(K198N), and NOS3(G894T) polymorphisms in the three-locus model were attributed to be the best models for predicting susceptibility to IPAH, with a P value of 0.05. CONCLUSION: MDR method can be useful in understanding the role of epistatic and gene-environmental interactions in pathogenesis of IPAH.

Contribution of sudden cardiac death to total mortality in India - a population based study.

INTRODUCTION: Epidemiology of sudden cardiac death (SCD) in India is understudied. METHODS: We assessed proportion of SCD among total mortality in a population in Southern India using a staged, questionnaire-based kindred-wide approach. Detailed questionnaires (DQs) were completed by medical trainees from 8 medical colleges. Preliminary questionnaires evaluated total deaths in the kindred of a respondent. Deaths due to obvious non-cardiac causes were excluded. DQs were completed for the remaining deaths and categorized using a three-member adjudication system. RESULTS: A total population of 22,724 was evaluated by 478 respondents, (278 M and 200 F). Out of a total of 2185 deaths, 1691 (77.4%) were recallable. A total of 173 (10.3%; 128 M and 45 F; mean age - 60.8 ± 14 years) deaths were adjudicated as SCD. Of these, 82 (47.3%) were ≤ 60 years of age. Prior MI, LV dysfunction and prior aborted SCD were found in 33.5%, 22.5% and 5.7% respectively. Coronary artery disease (CAD) was observed in 66 (38%) and acute myocardial infarction documented in 30 (17%). At least 1 of 3 CAD risk factors - hypertension, diabetes, or smoking was observed in 80.6%. Proportion of subjects with at least one risk factor for CAD were similar in the age groups above and below 50 years (67.6% vs. 81.7%, p=0.065). CONCLUSIONS: SCD contributed to 10.3% of overall mortality in this population from Southern India. On an average, SCD cases were 5-8 years younger compared to populations reported in the western hemisphere, with a high prevalence of major risk factors for CAD.

Sudden cardiac death after acute ST elevation myocardial infarction: insight from a developing country.

BACKGROUND: There is no data concerning sudden cardiac death (SCD) following acute ST elevation myocardial infarction (STEMI) in India. We assessed the incidence and factors influencing SCD following STEMI. METHODS: Patients with STEMI admitted in our hospital from 2006 to 2009 were prospectively entered into a database. In the period 2010-2011, patients or their kin were periodically contacted and administered a questionnaire to ascertain their survival, and mode of death if applicable. RESULTS: Study population comprised of 929 patients with STEMI (mean age 55±17 years) having a mean follow-up of 41±16 months. The total number of deaths was 159, of which 78 were SCD (mean age 62.2±10 years). The cumulative incidence of total deaths and SCD at 1 month, 1, 2, 3 years and at conclusion of the study was 10.1%, 13.2%, 14.6%, 15.8%, 17.3% and 4.9%, 6.5%, 8.0%, 8.9% and 9.7%, respectively. The temporal distribution of SCD was 53.9% at first month, 19.2% at 1 month to 1 year, 15.4% in 1-2 years, 7.6% in 2-3 years and 3.8% beyond 3 years. Comparison between SCD and survivor cohorts by multivariate analysis showed five variables were found to be associated with SCD (age p=0.0163, female gender p=0.0042, severe LV dysfunction p=0.0292, absence of both reperfusion and revascularisation p=0.0373 and lack of compliance with medications p <0.0001). CONCLUSIONS: SCD following STEMI accounts for about half of the total deaths. It involves younger population and most of these occur within the first month. This data has relevance in prioritising healthcare strategies in India.