Current Cardiology Reviews - Volume 17, Issue 6, 2021

There have many major history-defining epidemics and pandemics in the 21^st century. It is well known that acute infections can cause cardiovascular (CV) complications, especially in those with underlying cardiac disease. The variation in rates and types of CVD complications in major 21^st century epidemics and pandemics varies greatly. The coronavirus disease 2019 (COVID-19) pandemic has caused the turmoil of the century and has COVID-19 has resulted in substantial human and economic loss. The novelty of COVID-19 and emerging CV effects is a new entity. In this review, we discuss the major epidemics and pandemics of the 21^st century and associated CVD complications.

Background: Radiofrequency catheter ablation is a well-established treatment for several cardiac arrhythmias. Arrhythmias originating from the left side of the heart including ventricular and supraventricular tachycardia and ectopy can be successfully ablated through either transseptal or retrograde aortic approach. Although these techniques have a generally low rate of complications, aortic valve injury is a potential complication of ablation at the left cardiac side that warrants more investigation. Objective: The purpose of this review is to evaluate the incidence of iatrogenic aortic valve regurgitation and explore the potential mechanisms and risk factors that might contribute to aortic valve injury during radiofrequency ablation. Additionally, the course and progression of aortic regurgitation in the reported cases will be described. Methods: Authors searched PubMed for articles using the keywords “ablation” AND “aortic insufficiency” OR “aortic valve injury” OR “aortic regurgitation”. Case reports and series as well as retrospective and prospective studies were included, and relevant review articles and editorial comments were used as a supplementary source of data. A total of 19 references were used and a detailed description of patient characteristics, procedural techniques, and incidence, predictors, and fate of aortic regurgitation were reported by 11 clinical studies. Results: There is a small risk of significant iatrogenic aortic regurgitation after radiofrequency ablation of left-sided cardiac arrhythmias, especially techniques performed via a retrograde aortic approach. Conclusion: Although the risk is not confined to procedures applying direct energy to the aortic cusp region, a more aggressive ablation applied in the vicinity of the valvular complex seems to be associated with a higher risk. Routine post-procedural surveillance should be adopted to detect de novo aortic valve injury following radiofrequency ablation techniques.

Atrial natriuretic peptide (ANP) is a cardiac peptide with multiple physiological effects, including natriuresis, blood pressure regulation, and renin-angiotensin-aldosterone system (RAAS) antagonism. Pre-proANP is synthesized in the atria and must be extensively cleaved by the protease corin to produce the mature 28 amino acid ANP. The downstream signaling pathway of ANP acts through the guanylyl cyclase receptor and the second messenger cGMP. Studies on ANP’s physiological effects have demonstrated its activity on channels present in the apical membrane in the renal nephron, potentially inhibiting or decreasing sodium reabsorption. Recent research has also identified several clinical conditions, such as dilated cardiomyopathy, renal failure, and aging, associated with increased and decreased ANP levels. ANP levels could serve as a potential biomarker for the diagnosis of acute stages of heart failure, and ANP infusion could have a role in the management of acute or chronic heart failure.

Background: Coronavirus disease 2019 (Covid-19) pandemic is a global health crisis that has culminated in thousands of deaths. In order to reduce the spread of the Sars-CoV-2 virus, governments of several countries have adopted social isolation as a strategy. However, social isolation has culminated in deleterious effects on the population’s health, including increased physical inactivity, stress and, consequently, adverse changes in body composition, cardiorespiratory capacity, muscle strength, physical functionality, and vascular events, which are increasingly pointed out as the main determinants of cardiovascular health. Staying physically active during lockdown is a challenge, especially for the population with a higher risk of mortality from COVID-19, who are still encouraged to maintain social distance until there is a vaccine available. Strategies to avoid physical inactivity and reduce stress levels can promote cardiovascular protection and must be considered during COVID-19 time. Objective: The aim of this paper is to discuss the risks of physical inactivity and stress for the cardiovascular system during the COVID-19 pandemic and propose strategies to protect cardiovascular health. Conclusion: A home-based training protocol could be an interesting and effective strategy for the population who need to remain physically active and safe at home.

One in three Americans report experiencing loneliness in everyday life, a number that has grown exponentially over the last few decades. As we respond to the SARS-COV2 pandemic with quarantine and social distancing, social isolation and feelings of loneliness are increasing among people of all ages. This presents as an opportune time to recognize the public health impact of these important psychosocial determinants. Loneliness and social isolation are associated with a higher incidence of CVD, higher healthcare utilization and worse outcomes even after controlling for conventional risk factors of CVD. In this review, we discuss loneliness and social isolation as determinants of cardiovascular outcomes, the pathophysiology of this association, and its implications in clinical practice. We discuss some of the shortcomings in the assessment of loneliness and social isolation while identifying the most commonly used rating scales for the same. Finally, we suggest modifications to interventions for loneliness and social isolation during the COVID-19 pandemic.

Fontan operation has been defined as a palliative surgery connecting systemic venous return and pulmonary circulation in patients with certain forms of complex congenital heart disease (CHD). Fortunately, it has improved overall survival and chance of successful pregnancies among these patients. However, Fontan circulation (FC), as a potential trade-off, might be associated with specific late or post-gestational complications, including peripartum cardiomyopathy (PPCM) largely through its adverse effects on the placenta and inflammation-oxidation stress. Importantly, diagnosis of superimposed PPCM in women with FC might be a diagnostic challenge, requiring a high index of suspicion. Accordingly, the present paper aims to highlight the potential association of FC with PPCM evolution largely based on certain mechanistic and clinical perspectives.

Background: Globally, dyslipidemia has been shown to be an independent predictor of many cardiovascular and cerebrovascular events, which led to recent advocacy towards dyslipidemia prevention and control as a key risk factor and its prognostic significance to reduce the burden of stroke and myocardial infarction (MI). Aims: This study aimed to evaluate hyperlipidemia as a risk factor connected with stroke and CVD. Moreover, having identified this risk factor, the study evaluates how hyperlipidemia has been examined earlier and what can be done in the future. Methods: All prospective studies concerning hyperlipidemia as risk factors for stroke and CVD were identified by a search of PubMed/MEDLINE and EMBASE databases with keywords hyperlipidemia, risk factors, stroke, and cardiovascular disease. Results: The constant positive association between the incidence of coronary heart disease and cholesterol concentration of LDL is apparent in observational studies in different populations. Thus, the reduction of LDL cholesterol in those populations, particularly with regard to initial cholesterol concentrations, can reduce the risk of vascular diseases. However, the impact of using lipid-lowering drugs, such as statins, has been demonstrated in several studies as an important factor in decreasing the mortality and morbidity rates of patients with stroke and CVD. Conclusion: After reviewing all the research mentioned in this review, most studies confirmed that hyperlipidemia is a risk factor for stroke and correlated in patients with CVD.

Background: The optimal duration of dual antiplatelet therapy is a matter of ongoing research. Clinical studies are assessing the optimal duration with the most favourable risk to benefit ratio. The efficacy of P2Y12 receptor inhibitors comparable to aspirin in preventing recurrent ischaemic events in patients with coronary artery diseases. Objectives: To investigate the outcomes of short-duration dual antiplatelet therapy after PCI with early discontinuation of aspirin while maintaining patients on P2Y12 inhibitor through systematic review and meta-analysis of available literature. Methods: We systematically searched PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), and ClinicalTrials.gov. We included randomized controlled studies that measured clinical outcomes of efficacy (mortality and ischaemic events) and safety (bleeding) of short and standard-duration dual antiplatelet therapy. The protocol of this study was registered in the international prospective register of systematic reviews PROSPERO registry (CRD42020171468). Results: Four randomized controlled trials were included; GLOBAL LEADERS, SMARTCHOICE, STOPDAPT-2, and TWILIGHT. The total number of patients was 29,089. The safety outcomes showed a significant reduction in major bleeding events with short-duration dual antiplatelet therapy; the risk ratio was 0.61 (95% CI 0.38-0.99; z=2,00, p=0.05). There was no difference between short and standard-duration dual antiplatelet therapy regarding efficacy outcomes (all- cause death, major adverse cardiovascular events, myocardial infarction, stroke, and stent thrombosis). Conclusion: Short-duration dual antiplatelet therapy followed by P2Y12 inhibitor monotherapy after PCI is a feasible option and can be adopted, especially in patients with a high risk of bleeding.

Red cell distribution width (RDW) serves as an independent predictor towards the prognosis of coronary artery disease (CAD) in patients undergoing percutaneous coronary intervention (PCI). A systematic search of databases such as PubMed, Embase, Web of Science, and Cochrane library was performed on October 10^th, 2019, to elaborate the relationship between RDW and in hospital and long term follow up, all-cause and cardiovascular mortality, major adverse cardiac events (MACE) and development of contrast-induced nephropathy (CIN) in patients with CAD undergoing PCI. Twenty-one studies qualified this strict selection criterion (number of patients = 56,425): one study was prospective, and the rest were retrospective cohorts. Our analysis showed that patients undergoing PCI with high RDW had a significantly higher risk of in-hospital all-cause mortality (OR 2.41), long-term all-cause mortality (OR 2.44), cardiac mortality (OR 2.65), MACE (OR: 2.16), and odds of developing CIN (OR: 1.42) when compared to the patients with low RDW. Therefore, incorporating RDW in the predictive models for the development of CIN, MACE, and mortality can help in triage to improve the outcomes in coronary artery disease patients who undergo PCI.

Background: Once used by mountaineers to facilitate rapid adaptations to altitude and by athletes to improve their aerobic capacity, exposure to hypoxia has been proven to affect various physiological, clinically relevant parameters. A form of conditioning known as Intermittent Hypoxia Conditioning (IHC) consists of repeated exposures to intermittent hypoxia, combined with normoxia and hyperoxia, which has been shown to have potential as a treatment to improve cardio- metabolic risks profile in cardiac patients but results across studies are inconsistent. This systematic review and meta-analysis aimed to evaluate the clinical effectiveness of IHC. Methods: Four electronic databases (PubMed, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials) were searched (from inception to December 2019) to retrieve all studies focused on IHC in elderly patients with cardiovascular disease. A meta-analysis of functional, efficacy and safety outcomes in cardiac patients was completed to compare IHC to sham treatments. Results: Fourteen studies with 320 patients in the Interval Hypoxia-normoxia Group (IHNG) or Interval Hypoxia-hyperoxia training Group (IHHG) and 111 patients in the control group were included in our meta-analysis. IHNT and IHHT were associated with significant reduction in heart rate, SBP, and DBP at rest after treatment [MD= -5.35 beat/min, 95% CI (-9.19 to -1.50), p=0.006], [MD= -13.72 mmHg, 95% CI (-18.31 to -9.132), p<0.001], and [MD= -7.882 mmHg, 95% CI (-13.163 to -2.601), p=0.003], respectively. There were no significant complications or serious adverse events related to IHNT/IHHT. Conclusion: The current evidence suggested that the use of the IHNT/IHHT program in elderly patients with CVDs can be safe and effective in terms of heart rate and elevated blood pressure. However, currently, there is no supporting evidence that IHNT/IHHT can significantly improve hematological parameters or lipid profile. Exercise tolerance increased at the end of the course of hypoxic conditioning within IHC group, but did not differ from controls. Further research is needed.