Permanent Pacemaker Post Cardiac Surgery: where do we Stand?

Abstract Cardiac arrhythmias and requirement for permanent pacemaker (PPM) post open-heart surgery are some of the complications that can contribute to significant morbidities postoperatively and delay in normal recovery if not treated promptly. The reported rate of a PPM following isolated, elective coronary artery bypass grafting is < 1%, while following aortic or mitral valve surgery it is reported to be < 5%. There are several perioperative factors that can contribute to the increased likelihood of PPM requirement including preoperative rhythm, severity and location of cardiac ischaemia, perioperative variables, and the cardiac procedures performed. Optimization of such factors can possibly lead to a lower rate of PPM and, therefore, a lower rate of complications. This literature review focuses on PPM following each procedural type and how to minimize it.

Skeletonized or Pedicled Harvesting of Left Internal Mammary Artery: A Systematic Review and Meta-analysis.

We sought to compare clinical outcomes in skeletonized versus pedicled left internal mammary artery (LIMA) grafts in elective coronary artery bypass grafting through a systematic review and meta-analysis. A comprehensive electronic literature search of PubMed, Ovid, Embase, and Scopus was conducted from inception to January 2020. Only short-term (30 days) studies which compared both techniques have been included in our analysis. Primary outcomes were post anastomosis flow rate and sternal wound infection rate (SWI); secondary outcomes were conduit length, acute myocardial infarction and 30-day mortality. Thirteen articles with a total of 6222 patients met the inclusion criteria. Except for the prevalence of diabetes mellitus being significantly lower in the skeletonized cohort (odds ratio [OR] 0.77 95% confidence interval [CI] [0.61, 0.97], P = 0.03), there were no differences in the preoperative demographics between the 2 groups. The skeletonized LIMA conduit was significantly longer when compared to the pedicled conduit (weighted mean difference -2.64 cm 95% CI [-3.71, -1.56], P < 0.0001). SWI rates were not significantly different in the skeletonized versus pedicled LIMA group (OR 0.71 95% CI [0.47, 1.06], P = 0.10). New onset of acute myocardial infarction and 30-day mortality rate was similar in the 2 groups (OR 1.04 and 0.97, respectively, P > 0.05 in both). The postanastomoses flow rate was higher in skeletonized LIMA (Weighted Mean Difference -11.51 mL/min 95% CI [-20.54, -2.49], P < 0.01). Harvesting the LIMA using the skeletonized technique is associated with higher postanastomosis flow rates and longer conduit lengths; with no difference in SWI and mortality rates when compared to the pedicled technique. We suggest that this technique should be adopted, particularly for BITA harvesting. However, further research is needed to provide clearer indications for both methods.

Spontaneous coronary artery dissection: presentation and management options.

Coronary artery dissection is a serious, life-threatening heart condition. It can occur spontaneously or due to traumatic or iatrogenic causes. Spontaneous coronary artery dissection (SCAD) is often misdiagnosed as most patients present with symptoms resembling those of an acute coronary syndrome. Clinical sequelae of SCAD include debilitating morbidities such as myocardial infarction, myocardial ischaemia, sudden cardiac death, ventricular arrhythmias amongst many other myocardial ischaemia associated complications. There are two main methods of managing patients with SCAD; conservative management with medical therapy or revascularisation by percutaneous coronary intervention or coronary artery bypass grafting.

Coronary artery bypass grafting: Factors affecting outcomes.

INTRODUCTION: Coronary artery bypass grafting forms the bulk of a cardiac surgeon's workload. An extensive amount of research has been undertaken to improve the outcomes of this procedure. This literature review aimed to summarize key areas that influence coronary artery bypass grafting in modern day practice. METHODS: A comprehensive electronic search was done using PubMed, Ovid, SCOPUS, Embase and google scholar from inception to July 2020. Articles were included if they discussed factors affecting outcomes in coronary bypass grafting (CABG). Case reports, expert opinion, and editorials were excluded. RESULTS: There are many factors that influence and predict outcomes following coronary artery bypass surgery. Age, diabetes, and isolated systolic hypertension were preoperative factors with strong correlation to mortality and morbidity rates post CABG. In addition to these, the degree of renal failure and heart failure correlated with poorer operative results. The use of the left internal mammary artery has transformed outcomes and has proven advantage over venous conduit use. Newer minimal invasive techniques have the potential to further optimize outcomes. CONCLUSION: The numerous and complex factors which impair outcomes following CABG need to be further researched and addressed using larger trials and possible optimization of multi-disciplinary team approach to further improve long term outcomes.

Factors Affecting Outcomes in Acute Type A Aortic Dissection: A Systematic Review.

Acute type A aortic dissection is a clinical emergency and is associated with significant morbidity and mortality rates if not managed promptly in specialised and high-volume centres. The mortality rate is increased by 1% for each hour delay in management; however, with advancement in clinical practice, diagnostic imaging and clinician awareness, this has been dramatically reduced to below 30% in most international centres. Not only timing of recognition of the pathology, but also other factors can significantly affect outcomes of such critical pathology. This includes, but is not limited to, age, extent of the pathology, existence of connective tissue disorders, hypertension, diabetes mellitus and surgeon experience. This narrative review will focus on current clinical practice and the evidence behind optimising each factor to minimise adverse outcomes in such high-risk cohort.

The role of biomarkers in diagnosis of COVID-19 - A systematic review.

AIMS: As of the 28th April 2020, the COVID-19 pandemic has infiltrated over 200 countries and affected over three million confirmed people. We review different biomarkers to evaluate if they are able to predict clinical outcomes and correlate with the severity of COVID-19 disease. METHODS: A systematic review of the literature was carried out to identify relevant articles using six different databases. Keywords to refine the search included 'COVID-19', 'SARS-CoV2', 'Biomarkers', among others. Only studies which reported data on pre-defined outcomes were included. KEY FINDINGS: Thirty-four relevant articles were identified which reviewed the following biomarkers: C-reactive protein, serum amyloid A, interleukin-6, lactate dehydrogenase, neutrophil-to-lymphocyte ratio, D-dimer, cardiac troponin, renal biomarkers, lymphocytes and platelet count. Of these, all but two, showed significantly higher levels in patients with severe complications of COVID-19 infection compared to their non-severe counterparts. Lymphocytes and platelet count showed significantly lower levels in severe patients compared to non-severe patients. SIGNIFICANCE: Although research is still in its early stages, the discovery of how different biomarkers behave during the course of the disease could help clinicians in identifying severe disease earlier and subsequently improve prognosis. Nevertheless, we urge for more research across the globe to corroborate these findings.