Global Cardiology Science and Practice - Volume 2015, Issue 2

We examine the one-year mortality rates from the STREAM trial, recently published in Circulation.

Genetic variants have been associated with the risk of coronary heart disease (CHD). Mega et al studied the association of a genetic risk score based on 27 genetic variants with incidents of recurrent CHD, adjusting for traditional risk factors using data from a community based study and 4 randomized controlled trials of both primary and secondary prevention with statin therapy. When individuals were divided into low, intermediate and high genetic risk categories, a significant gradient in risk of incident and recurrent CHD was shown.

Proprotein convertase subtilisin kexin 9 (PCSK9) inhibitors have emerged as a novel treatment option in patients with hypercholesterolemia. Evolocumab and alirocumab have achieved consistent and significant (around 60%) reduction in low-density lipoprotein cholesterol (LDL-C) levels when added to statin therapy in short term studies. The Open-Label Study of Long-term Evaluation Against LDL-C (OSLER), and The Long-term Safety and Tolerability of Alirocumab in High Cardiovascular Risk Patients with Hypercholesterolemia Not Adequately Controlled with Their Lipid Modifying Therapy (ODYSSEY LONG TERM) studies are two phase 3, multicentre, randomized, placebo controlled studies that were conducted to evaluate the long term efficacy and safety of evolocumab and alirocumab respectively in reducing lipids and cardiovascular (CV) events. Both studies demonstrated additional 48–53% reduction of CV events when added to statin therapy. Most adverse events occurred with similar frequency in the two groups; however the rate of neurocognitive adverse events was higher with evolocumab and alirocumab than with placebo. These data provide strong support for the notion that lower LDL-C goal is better, and may confirm the role of PCSK9 inhibitors as a new frontier in lipid management. The results of larger long-term outcome studies are still awaited.

The introduction of transcatheter aortic valve replacement (TAVR in US - TAVI in Europe) has resulted in a paradigm shift in the treatment of patients with severe aortic stenosis. Although three randomized trials and multiple single-center and multicenter registry studies have been published, the profile and longer-term outcome of patients undergoing transcatheter aortic valve replacement (TAVR) in patients with severe aortic stenosis have been limited. The recently published reports from the United Kingdom (UK)¹ and United States (US)² TAVR registries add tremendously to the currently available literature. These studies provide an excellent model to clinicians that would aid in the proper patient selection and help in guiding discussions with patients who are undergoing TAVR. The present review discusses the recently published UK and US TAVR registry data.

Burundi is one of the world's poorest nations, which is also reflected in its relative lack of cardiac facilities, particularly those catering to young children and adults. The authors discuss current efforts to build “The Burundi Heart Centre” to help address this challenge. In particular, they highlight how the project can act as a case study for a sustainable architecture that involves local people and uses locally available materials in a contemporary and innovative way.

Mass spectrometry is a powerful technique that is used to identify unknown compounds, to quantify known materials, and to elucidate the structure and chemical properties of molecules. Recent advances in the accuracy and speed of the technology have allowed data acquisition for the global analysis of lipids from complex samples such as blood plasma or serum. Here, mass spectrometry as a tool is described, its limitations explained and its application to biomarker discovery in coronary artery disease is considered. In particular an application of mass spectrometry for the discovery of lipid biomarkers that may indicate plaque morphology that could lead to myocardial infarction is elucidated.

Congenital long QT syndrome, caused by a cardiac channelopathy, is a leading cause of sudden cardiac death in the young population. In total, 16 genes have been implicated in this condition, with three genes being the most commonly affected. Long QT syndrome is one of the earliest conditions for which a genotype specific treatment was designed. This genotype-phenotype correlation extends to involve the clinical presentation, electrocardiographic manifestation and treatment strategies. It is necessary for the clinician treating these patients to be cognizant of the important role played by the genotype in order to best provide counseling and treatment options to this unique population.

Background: Ventricular-vascular coupling is an important phenomenon in many cardiovascular diseases. The association between aortic mechanical dysfunction and left ventricular (LV) dysfunction is well characterized in many disease entities, but no data are available on how these changes are related in hypertrophic cardiomyopathy (HCM). Aim of the work: This study examined whether HCM alone is associated with an impaired aortic mechanical function in patients without cardiovascular risk factors and the relation of these changes, if any, to LV deformation and cardiac phenotype. Methods: 141 patients with HCM were recruited and compared to 66 age- and sex-matched healthy subjects as control group. Pulse pressure, aortic strain, stiffness and distensibility were calculated from the aortic diameters measured by M-mode echocardiography and blood pressure obtained by sphygmomanometer. Aortic wall systolic and diastolic velocities were measured using pulsed wave Doppler tissue imaging (DTI). Cardiac assessment included geometric parameters and myocardial deformation (strain and strain rate) and mechanical dyssynchrony. Results: The pulsatile change in the aortic diameter, distensibility and aortic wall systolic velocity (AWS') were significantly decreased and aortic stiffness index was increased in HCM compared to control (P < .001) In HCM AWS' was inversely correlated to age(r = − .32, P < .0001), MWT (r = − .22, P < .008), LVMI (r = − .20, P < .02), E/Ea (r = − .16, P < .03) LVOT gradient (r = − 19, P < .02) and severity of mitral regurg (r = − .18, P < .03) but not to the concealed LV deformation abnormalities or mechanical dyssynchrony. On multivariate analysis, the key determinant of aortic stiffness was LV mass index and LVOT obstruction while the role LV dysfunction in aortic stiffness is not evident in this population. Conclusion: HCM is associated with abnormal aortic mechanical properties. The severity of cardiac phenotype, not LV deformation, is interrelated to aortic stiffness in patients with HCM. The increased aortic stiffness seems to be promising module that can be added as clinical risk parameter in HCM.

Background: Angina that is refractory to conventional medical therapy and revascularisation, remains challenging to manage and poses significant burden to patients. Elevated lipoprotein(a) [Lp(a)] has emerged as an important independent cardiovascular risk factor and predictor of adverse outcomes in atherosclerotic disease. The prevalence of raised Lp(a) amongst patients with refractory angina has not yet been defined. Objective: To establish the prevalence of raised [Lp(a)] >500 mg/L in patients with refractory angina. Methods: We conducted an epidemiological screening pilot study in 75 patients with refractory angina from a UK tertiary cardiac centre. We determined the proportion of the cohort with raised Lp(a) >500 mg/L using an isoform-insensitive method. In addition, a full fasting lipid profile (including: LDL cholesterol, HDL cholesterol, total cholesterol to HDL ratio and triglycerides) was obtained. Patients were also asked about the presence of conventional cardiovascular risk factors. Results: Our study demonstrated that 60% of the 75 patients with refractory angina had raised Lp(a) levels of >500 mg/L. The median and inter-quartile range of Lp(a) values were 771 mg/L (162 mg/L,1260 mg/L) respectively. Conclusions: This high prevalence of raised Lp(a) detected in our cohort with refractory angina may suggest a causal role. Further research is necessary to confirm this association and prospective studies are needed to explore the potential therapeutic benefit of Lp(a) reduction in patients with refractory angina.