Surgical or Percutaneous Repair of Sinus of Valsalva Rupture: Case Series and Literature Review.

The rupture of the sinus of the Valsalva aneurysm is a rare but very serious condition. Rapid and accurate diagnosis and prompt treatment are critical for these cases. We present two cases of sinus of Valsalva ruptures. One case was managed with open surgical repair and the second case was treated percutaneously. We have discussed these two therapeutic approaches available to treat sinus of Valsalva rupture.

Mackay Heart Failure Study: Examining the Root Causes, Compliance With Guideline-Based Therapy and Prognosis.

INTRODUCTION: Heart failure patients have poor outcomes comparable to some malignancies; however, the modern guideline directed medical therapy (GDMT) has improved its outcomes. The clinical characteristics and prescribers' compliance with GDMT for heart failure patients have not been studied in the Mackay region. METHODS: A retrospective cohort study of 115 consecutive adult heart failure patients was conducted at our institution. RESULTS: The study cohort consisted of 80% (n=92) males. Ischaemia was the leading cause accounting for 54% (n=62) of the cohort, followed by idiopathic cardiomyopathy at 32% (n=37). Drug-induced and Takotsubo cardiomyopathies were responsible for 11% and 1% respectively. Two (2) patients (2%) had valvular heart disease. Hypertension was present in 57% while diabetes and atrial fibrillation were present in 32% and 43% of patients. Fifty-nine per cent (59%) had a smoking history. All, except four patients, had reduced left ventricular ejection fraction (LVEF <50%) at diagnosis. Among patients with coronary ischaemia, 37% and 31% were revascularised with percutaneous coronary interventions and bypass graft surgeries, respectively. Renin-angiotensin-aldosterone system inhibitors and beta blockers were prescribed in 94% and 95% of the patients, respectively. Mineralocorticoid inhibitors were used in 25% while ivabradine was given to 8% of patients. Nine per cent (9%) of patients received cardiac resynchronisation therapy. Most patients had improvement in functional class and LVEF during follow-up. There were very few mortalities at 3% (n=3) at the median follow-up of 403 (IQR 239-896) days. CONCLUSION: Our study has shed light on heart failure epidemiology in the Mackay region. We found excellent compliance with GDMT and good prognosis for most patients in terms of both symptom and survival.

Effects of the coronary artery disease associated LPA and 9p21 loci on risk of aortic valve stenosis.

BACKGROUND: Aortic valve stenosis (AVS) and coronary artery disease (CAD) have a significant genetic contribution and commonly co-exist. To compare and contrast genetic determinants of the two diseases, we investigated associations of the LPA and 9p21 loci, i.e. the two strongest CAD risk loci, with risk of AVS. METHODS: We genotyped the CAD-associated variants at the LPA (rs10455872) and 9p21 loci (rs1333049) in the GeneCAST (Genetics of Calcific Aortic STenosis) Consortium and conducted a meta-analysis for their association with AVS. Cases and controls were stratified by CAD status. External validation of findings was undertaken in five cohorts including 7880 cases and 851,152 controls. RESULTS: In the meta-analysis including 4651 cases and 8231 controls the CAD-associated allele at the LPA locus was associated with increased risk of AVS (OR 1.37; 95%CI 1.24-1.52, p = 6.9 × 10-10) with a larger effect size in those without CAD (OR 1.53; 95%CI 1.31-1.79) compared to those with CAD (OR 1.27; 95%CI 1.12-1.45). The CAD-associated allele at 9p21 was associated with a trend towards lower risk of AVS (OR 0.93; 95%CI 0.88-0.99, p = 0.014). External validation confirmed the association of the LPA risk allele with risk of AVS (OR 1.37; 95%CI 1.27-1.47), again with a higher effect size in those without CAD. The small protective effect of the 9p21 CAD risk allele could not be replicated (OR 0.98; 95%CI 0.95-1.02). CONCLUSIONS: Our study confirms the association of the LPA locus with risk of AVS, with a higher effect in those without concomitant CAD. Overall, 9p21 was not associated with AVS.

Large-Scale Analysis of Determinants, Stability, and Heritability of High-Density Lipoprotein Cholesterol Efflux Capacity.

OBJECTIVE: Cholesterol efflux capacity (CEC) has emerged as a biomarker of coronary artery disease risk beyond plasma high-density lipoprotein (HDL) cholesterol (HDL-C) level. However, the determinants of CEC are incompletely characterized. We undertook a large-scale family-based population study to identify clinical, biochemical, and HDL particle parameter determinants of CEC, characterize reasons for the discordancy with HDL-C, quantify its heritability, and assess its stability over 10 to 12 years. APPROACHES AND RESULTS: CEC was quantified in 1988 individuals from the GRAPHIC (Genetic Regulation of Arterial Pressure of Humans in the Community) cohort, comprising individuals from 2 generations from 520 white nuclear families. Serum lipid and lipoprotein levels were determined by ultracentrifugation or nuclear magnetic resonance and HDL particle size and number quantified by nuclear magnetic resonance. Ninety unrelated individuals had repeat CEC measurements in samples collected after 10 to 12 years. CEC was positively correlated with HDL-C (R=0.62; P<0.0001). Among clinical and biochemical parameters, age, systolic blood pressure, alcohol consumption, serum albumin, triglycerides, phospholipids, and lipoprotein(a) were independently associated with CEC. Among HDL particle parameters, HDL particle number, particle size, and apolipoprotein A-II level were independently associated with CEC. Serum triglyceride level partially explained discordancy between CEC and HDL-C. CEC measurements in samples collected 10 to 12 years apart were strongly correlated (r=0.73; P<0.0001). Heritability of CEC was 0.31 (P=3.89×10-14) without adjustment for HDL-C and 0.13 (P=1.44×10-3) with adjustment. CONCLUSIONS: CEC is a stable trait over time, is influenced by specific clinical, serum, and HDL particle parameters factors beyond HDL-C, can be maintained in persons with a low plasma HDL-C by elevated serum triglyceride level, and is modestly independently heritable.

Analysis of gene-gene interactions among common variants in candidate cardiovascular genes in coronary artery disease.

OBJECTIVE: Only a small fraction of coronary artery disease (CAD) heritability has been explained by common variants identified to date. Interactions between genes of importance to cardiovascular regulation may account for some of the missing heritability of CAD. This study aimed to investigate the role of gene-gene interactions in common variants in candidate cardiovascular genes in CAD. APPROACH AND RESULTS: 2,101 patients with CAD from the British Heart Foundation Family Heart Study and 2,426 CAD-free controls were included in the discovery cohort. All subjects were genotyped with the Illumina HumanCVD BeadChip enriched for genes and pathways relevant to the cardiovascular system and disease. The primary analysis in the discovery cohort examined pairwise interactions among 913 common (minor allele frequency >0.1) independent single nucleotide polymorphisms (SNPs) with at least nominal association with CAD in single locus analysis. A secondary exploratory interaction analysis was performed among all 11,332 independent common SNPs surviving quality control criteria. Replication analyses were conducted in 2,967 patients and 3,075 controls from the Myocardial Infarction Genetics Consortium. None of the interactions amongst 913 SNPs analysed in the primary analysis was statistically significant after correction for multiple testing (required P<1.2x10-7). Similarly, none of the pairwise gene-gene interactions in the secondary analysis reached statistical significance after correction for multiple testing (required P = 7.8x10-10). None of 36 suggestive interactions from the primary analysis or 31 interactions from the secondary analysis was significant in the replication cohort. Our study had 80% power to detect odds ratios > 1.7 for common variants in the primary analysis. CONCLUSIONS: Moderately large additive interactions between common SNPs in genes relevant to cardiovascular disease do not appear to play a major role in genetic predisposition to CAD. The role of genetic interactions amongst less common SNPs and with medium and small magnitude effects remain to be investigated.

Resuscitated cardiac arrest and prognosis following myocardial infarction.

OBJECTIVES: To determine whether resuscitated cardiac arrest (CA) complicating ST elevation myocardial infarction (STEMI) impacts outcome, particularly in patients surviving to discharge. BACKGROUND: Resuscitated CA complicating STEMI is associated with increased inpatient mortality. The impact on later prognosis is unclear. METHODS: We analysed data from the UK Myocardial Ischaemia National Audit Project for STEMI patients admitted during January 2008-March 2010. We used survival analyses to assess the independent impact of resuscitated CA during the index episode on inhospital, 30 days, 1 year and medium term all-cause mortality. RESULTS: Of 48 749 STEMI patients, 5308 (10.9%) were recorded as having a CA. Of these, 1557 (29.3%) died on the day of CA. In survivors, after covariate adjustment, resuscitated CA was associated with increased risk of death during the index admission (HR 4.05 (3.69 to 4.45) p<0.001). In patients surviving to discharge, a history of resuscitated CA was associated with increased risk of death to 30 days (HR 1.53 (1.18 to 2.00), p<0.001). However, beyond 30 days, resuscitated CA was not associated with increased mortality risk (1-year HR 0.95 (0.79 to 1.14, p=0.596); 3.5 years HR 0.90 (0.78 to 1.04), p=0.144). The influence of resuscitated CA on inhospital or 30-day mortality was similar whether CA occurred before or after hospital admission. Where the resuscitated CA rhythm was asystole, inhospital mortality was higher compared with ventricular arrhythmia (p<0.001) or pulseless electrical activity (p=0.011). Late resuscitated CA (occurring after the day of index STEMI) was associated with higher 30-day postdischarge mortality compared with early resuscitated CA (p=0.023). CONCLUSIONS: STEMI complicated by resuscitated CA merits careful monitoring in the early period postevent. In contemporary practice, there is no impact of resuscitated CA on longer-term prognosis.

Hypothesis-based analysis of gene-gene interactions and risk of myocardial infarction.

The genetic loci that have been found by genome-wide association studies to modulate risk of coronary heart disease explain only a fraction of its total variance, and gene-gene interactions have been proposed as a potential source of the remaining heritability. Given the potentially large testing burden, we sought to enrich our search space with real interactions by analyzing variants that may be more likely to interact on the basis of two distinct hypotheses: a biological hypothesis, under which MI risk is modulated by interactions between variants that are known to be relevant for its risk factors; and a statistical hypothesis, under which interacting variants individually show weak marginal association with MI. In a discovery sample of 2,967 cases of early-onset myocardial infarction (MI) and 3,075 controls from the MIGen study, we performed pair-wise SNP interaction testing using a logistic regression framework. Despite having reasonable power to detect interaction effects of plausible magnitudes, we observed no statistically significant evidence of interaction under these hypotheses, and no clear consistency between the top results in our discovery sample and those in a large validation sample of 1,766 cases of coronary heart disease and 2,938 controls from the Wellcome Trust Case-Control Consortium. Our results do not support the existence of strong interaction effects as a common risk factor for MI. Within the scope of the hypotheses we have explored, this study places a modest upper limit on the magnitude that epistatic risk effects are likely to have at the population level (odds ratio for MI risk 1.3-2.0, depending on allele frequency and interaction model).

Genetic associations with lipoprotein subfractions provide information on their biological nature.

Adverse levels of lipoproteins are highly heritable and constitute risk factors for cardiovascular outcomes. Hitherto, genome-wide association studies revealed 95 lipid-associated loci. However, due to the small effect sizes of these associations large sample numbers (>100 000 samples) were needed. Here we show that analyzing more refined lipid phenotypes, namely lipoprotein subfractions, can increase the number of significantly associated loci compared with bulk high-density lipoprotein and low-density lipoprotein analysis in a study with identical sample numbers. Moreover, lipoprotein subfractions provide novel insight into the human lipid metabolism. We measured 15 lipoprotein subfractions (L1-L15) in 1791 samples using (1)H-NMR (nuclear magnetic resonance) spectroscopy. Using cluster analyses, we quantified inter-relationships among lipoprotein subfractions. Additionally, we analyzed associations with subfractions at known lipid loci. We identified five distinct groups of subfractions: one (L1) was only marginally captured by serum lipids and therefore extends our knowledge of lipoprotein biochemistry. During a lipid-tolerance test, L1 lost its special position. In the association analysis, we found that eight loci (LIPC, CETP, PLTP, FADS1-2-3, SORT1, GCKR, APOB, APOA1) were associated with the subfractions, whereas only four loci (CETP, SORT1, GCKR, APOA1) were associated with serum lipids. For LIPC, we observed a 10-fold increase in the variance explained by our regression models. In conclusion, NMR-based fine mapping of lipoprotein subfractions provides novel information on their biological nature and strengthens the associations with genetic loci. Future clinical studies are now needed to investigate their biomedical relevance.

Post-genomic update on a classical candidate gene for coronary artery disease: ESR1.

BACKGROUND: After age, sex is the most important risk factor for coronary artery disease (CAD). The mechanism through which women are protected from CAD is still largely unknown, but the observed sex difference suggests the involvement of the reproductive steroid hormone signaling system. Genetic association studies of the gene-encoding Estrogen Receptor α (ESR1) have shown conflicting results, although only a limited range of variation in the gene has been investigated. METHODS AND RESULTS: We exploited information made available by advanced new methods and resources in complex disease genetics to revisit the question of ESR1's role in risk of CAD. We performed a meta-analysis of 14 genome-wide association studies (CARDIoGRAM discovery analysis, N=≈87,000) to search for population-wide and sex-specific associations between CAD risk and common genetic variants throughout the coding, noncoding, and flanking regions of ESR1. In addition to samples from the MIGen (N=≈6000), WTCCC (N=≈7400), and Framingham (N=≈3700) studies, we extended this search to a larger number of common and uncommon variants by imputation into a panel of haplotypes constructed using data from the 1000 Genomes Project. Despite the widespread expression of ERα in vascular tissues, we found no evidence for involvement of common or low-frequency genetic variation throughout the ESR1 gene in modifying risk of CAD, either in the general population or as a function of sex. CONCLUSIONS: We suggest that future research on the genetic basis of sex-related differences in CAD risk should initially prioritize other genes in the reproductive steroid hormone biosynthesis system.

CO liberated from a carbon monoxide-releasing molecule exerts a positive inotropic effect in doxorubicin-induced cardiomyopathy.

Carbon monoxide (CO) liberated by a water-soluble carbon monoxide-releasing molecule (CORM-3) induces a positive inotropic effect with a negative chronotropic effect in normal rat hearts. However, the efficacy of CORM-3 under conditions of chronic cardiac insufficiency is unknown. In a rat model of doxorubicin-induced cardiomyopathy, CORM-3 (20 microg/min) produced a positive inotropic effect as demonstrated by significant increases in systolic pressure (P < 0.05) and pressure derivative (dp/dt max) over time (P < 0.05). A similar dose of CO-depleted negative control (inactive CORM-3) failed to cause any change in these parameters. When the inotrope dobutamine was added at a dose of 10 microM following CORM-3, there was no additional increase in systolic pressure or dp/dt max. However, significant rises in systolic pressure and dp/dt max were observed after dobutamine administration to the hearts previously treated with inactive CORM-3. These results suggest that CORM-3 produces a positive inotropic effect in doxorubicin cardiomyopathy rat hearts, similar to that reported previously in normal hearts. The inotropic effect produced by CO in the doxorubicin cardiomyopathy heart was mimicked by a classical inotrope (dobutamine), suggesting that either a maximal inotropic effect is achieved at this dose of CORM-3 or both drugs utilize shared signaling pathways in cardiac muscle.

Improved myocardial function after cold storage with preservation solution supplemented with a carbon monoxide-releasing molecule (CORM-3).

BACKGROUND: Carbon monoxide-releasing molecules (CO-RMs) are pharmacologically active as they protect against cardiac graft rejection and cold ischemia-mediated renal dysfunction. We investigated the cardioprotective role of carbon monoxide (CO) released from CORM-3 against cold ischemia-mediated injury in the heart and evaluated its potential application in the clinical setting of cardiac transplantation. METHODS: Isolated rat hearts underwent cold ischemic storage for 4 or 6 hours using St Thomas Hospital solution that was supplemented with either CORM-3 (50 mumol/liter) or its inactive counterpart (iCORM-3), which does not release CO. Hearts were then reperfused. Both functional parameters and release of cardiac enzymes were assessed. RESULTS: Addition of CORM-3 to the preservation solution resulted in a significant improvement in systolic and diastolic function as well as coronary flow when compared with hearts treated with iCORM-3. In addition, lower levels of the cardiac enzymes creatine kinase and lactate dehydrogenase were measured in the perfusate of hearts stored with CORM-3. CONCLUSIONS: The improved functional recovery and reduced enzyme release after cardiac cold storage with CORM-3, but not iCORM-3, indicate that CO is the main mediator of myocardial protection. Thus, CO-RMs can be used as adjuvants to improve the preservation of hearts for transplantation.