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.

Left Atrial or Transeptal Approach for Mitral Valve Surgery: A Systematic Review and Meta-analysis.

To compare outcomes of mitral valve surgery through conventional left atriotomy and transeptal approach (TS). Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. Primary outcomes were operative mortality and permanent pacemaker (PPM) implantation; secondary outcomes were new onset of atrial fibrillation (AF), stroke and operative times. Sixteen articles met the inclusion criteria with 4537 patients. Cardiopulmonary bypass was longer with TS (weighted mean differences - 16.44 minutes [-29.53, -3.36], P = 0.01). Rates of PPM implantation (risk ratio 0.65 [0.47, 0.89], P = 0.007) and new onset AF (risk ratio 0.87 [0.78, 0.97], P = 0.02) were higher with TS. Subgroup analysis of isolated mitral valve surgery cohort showed no difference in operative times, mortality, new onset of AF, stroke, and PPM implantation. There is equal outcomes between both approaches during isolated mitral valve surgery; however, TS was associated with longer operative times and higher postoperative AF and PPM rates when pooling combined procedures. A large randomized controlled trial is required to confirm those findings.

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.

The Current Management of Cardiac Tumours: a Comprehensive Literature Review.

OBJECTIVE: To understand the current evidence and guidelines behind the appropriate management of cardiac tumours. METHODS: A comprehensive electronic literature search has been performed in major databases - PubMed, Embase, Scopus, Ovid, and Google Scholar. All articles that discussed all different forms of cardiac tumours, their clinical presentation, diagnosis, and management methods have been critically appraised in this narrative review. RESULTS: All relevant studies have been summarized in appropriate sections within our review. Cardiac tumours are rare but can be catastrophic and life-threatening if not identified and managed on timely manner. Utilization of all the available imaging methods can be of equivocal importance, relevant to each cardiac tumour. Surgical excision is the ultimate treatment method, however histopathological results can guide the adjunct treatment. CONCLUSION: Early detection of cardiac tumours has significant effect on planning the method of intervention. Technological advancements and increased availability of imaging modalities have enabled earlier and more accurate detection of these tumours. Novel medical therapies, recommendations for screening, and operative techniques have all contributed to overall improving knowledge of these tumours and ultimately patient outcomes.

The current management of cardiac tumours: a comprehensive literature review

Abstract Objective: To understand the current evidence and guidelines behind the appropriate management of cardiac tumours. Methods: A comprehensive electronic literature search has been performed in major databases - PubMed, Embase, Scopus, Ovid, and Google Scholar. All articles that discussed all different forms of cardiac tumours, their clinical presentation, diagnosis, and management methods have been critically appraised in this narrative review. Results: All relevant studies have been summarized in appropriate sections within our review. Cardiac tumours are rare but can be catastrophic and life-threatening if not identified and managed on timely manner. Utilization of all the available imaging methods can be of equivocal importance, relevant to each cardiac tumour. Surgical excision is the ultimate treatment method, however histopathological results can guide the adjunct treatment. Conclusion: Early detection of cardiac tumours has significant effect on planning the method of intervention. Technological advancements and increased availability of imaging modalities have enabled earlier and more accurate detection of these tumours. Novel medical therapies, recommendations for screening, and operative techniques have all contributed to overall improving knowledge of these tumours and ultimately patient outcomes.

TAVI and the future of aortic valve replacement.

Aortic valve stenosis (AS) is the most common valvular pathology and has traditionally been managed using surgical aortic valve replacement (SAVR). A large proportion of affected patient demographics, however, are unfit to undergo major surgery given underlying comorbidities. Since its introduction in 2002, transcatheter aortic valve implantation (TAVI) has gained popularity and transformed the care available to different-risk group patients with severe symptomatic AS. Specific qualifying criteria and refinement of TAVI techniques are fundamental in determining successful outcomes for intervention. Given the successful applicability in high-risk patients, TAVI has been further developed and trialed in intermediate and low-risk patients. Within intermediate-risk patient groups, TAVI was shown to be noninferior to SAVR evaluating 30-d mortality and secondary endpoints such as the risk of bleeding, development of acute kidney injury, and length of admission. The feasibility of expanding TAVI procedures into low-risk patients is still a controversial topic in the literature. A number of trials have recently been published which demonstrate TAVI as noninferior and even superior over SAVR for primary study endpoints.

Comprehensive literature review of anomalies of the coronary arteries.

Coronary artery anomalies (CAA) are vanishingly rare, affecting less than 1% of the general population. While the majority of anomalies do not cause significant symptoms; those that do, have devastating outcomes on the patient. Seventeen percent of deaths from exercise is attributed to CAA, and over half of these present as sudden death making CAA the second most common cause of sudden cardiac death in individuals. Computed tomography is generally regarded as the first-line investigation due to its superior ability to delineate the course of the coronary vessels and the surrounding structures, while intravascular coronary angiography can be helpful in assessing the vessels if there is evidence of stenosis. A multidisciplinary approach is adopted with patient expectations at the core of the management. Once the decision to operate has been made, there are multiple techniques available to the surgeon for the management of anomalous vessels. Surgical repair forms the key management step in such patients. Currently, surgery in elective cases is associated with extremely low morbidity and mortality and it is considered a safe option with a fantastic long-term prognosis. The ideal approach for assessment and risk stratification remains uncertain, and the inherent variability of coronary anomalies and patient factors demands a multidisciplinary team with an individualized approach.

Can macrophages within the microenvironment of locally invasive rectal cancers predict response to radiotherapy?

BACKGROUND: Only half of patients with locally invasive rectal carcinoma respond to short-course preoperative radiotherapy. A predictive test enabling better patient selection could avoid unneccessary radiation exposure to poor responders. Macrophages within the tumour immune microenvironment with tumoricidal M1 and tumour-protective M2 phenotypes could be modulating this response. This study investigated the possible predictive value of M1 and M2 subpopulations in identifying patients' likely response to short-course preoperative radiotherapy. METHODS: Biopsy samples were taken from 29 patients with locally invasive rectal carcinoma before treatment with short-course radiotherapy and surgical specimens obtained after resection following short-course preoperative radiotherapy. Dual-staining immunohistochemistry was performed with CD68 as macrophage marker, HLA-DR as M1 marker, and CD163 as M2 marker. Samples were scored for hot-and-random spots by Nuance software (version 3.0.2) and compared with patients' outcome data. Tumour response was measured by assessment of reduction of tumour-cell density. FINDINGS: Samples revealing a low score for HLA-DR positive M1 macrophages exhibited a better response to short-course radiotherapy with up to 80% (median 80·38% [IQR 46·94-84·73]) reduction in the tumour cell density. On the other hand those with a high score exhibited a poor response with only up to 20% (20·26 [0-48·19]) reduction. The difference in response between the two groups was significant (p=0·017). No such trends were observed for CD163+ M2 macrophages. The ratio of HLA-DR+ to CD163+ macrophages for biopsy and resection samples was significantly different, showing a drop in the HLA-DR positive macrophages in the resection samples (p=0·024). The mean of the difference between the biopsy (median 2·53 [IQR 1·98-3·08]) and resection (1·38 [0·96-1·8]) was 1·15 (p=0·024). INTERPRETATION: Patients with a variable macrophage phenotype composition within biopsy samples from patients with locally invasive rectal carcinoma respond differently to short-course preoperative radiotherapy. Further investigation involving a panel of macrophage and other immune-cell markers could verify and validate these findings and develop them as predictive tests identifying good responders to radiotherapy in patients with locally invasive rectal carcinoma. FUNDING: None.