Pericardiectomy for Constrictive Pericarditis after Mediastinal Irradiation – Need for Functional AssessmentSiddharth Pahwa, MD1

Patients diagnosed with COVID-19 infection undergoing surgical procedures have been reported to have increased post-operative complications and mortality. These findings are important when considering cardiac surgical procedures, specifically coronary artery bypass grafting (CABG). This case series describes the clinical course following a CABG procedure in two patients that went on to develop COVID-19 infection post-operatively, having previously tested negative. We aim to illustrate the similarities in clinical presentation, but differences in eventual outcomes for both patients and hypothesize the reasons for the differences. Patients with comorbidities such as advanced age, diabetes mellitus, obesity, hypertension, and COPD are possibly at increased risk of adverse outcomes should they contract the infection, and special care should be taken in this population. Early institution of VV-ECMO may be beneficial, but further studies are needed in this matter.

Background Pericardiectomy for post-radiation constrictive pericarditis has been reported to generally have unfavorable outcomes. This study sought to evaluate surgical outcomes in a large cohort of patients undergoing pericardiectomy for radiation-associated pericardial constriction. Methods A retrospective analysis of all patients (≥18years) who underwent pericardiectomy for a diagnosis of constrictive pericarditis with a prior history of mediastinal irradiation from June 2002 to June 2019 was conducted. There were 100 patients (mean age 57.2±10.1 years, 49% females) who met the inclusion criteria. Records were reviewed to look at surgical approach, extent of resection, early mortality and late survival. Results The overall operative mortality was 10.1% (n=10). The rate of operative mortality decreased over the study period; however, the test of trend was not statistically significant (P=0.062). Hodgkin’s disease was the most common malignancy (64%) for which mediastinal radiation had been received. Only 27% patients had an isolated pericardiectomy, and concomitant pericardiectomy and valve surgery was performed in 46% patients. Radical resection was performed in 50% patients, whereas 47% patients underwent a subtotal resection. Prolonged ventilation (26%), atrial fibrillation (21%) and pleural effusion (16%) were the most common post-operative complications. The overall 1,5- and 10-years survival was 73.6%, 53.4% and 32.1% respectively. Increasing age (HR 1.044, 95%CI 1.017-1.073) appeared to have a significant negative effect on overall survival in the univariate model. Conclusion Pericardiectomy performed for radiation associated constrictive pericarditis has poor long-term outcomes. The early mortality, though high (~10%), has been showing a decreasing trend in the test of time.

Risk models were developed to provide clinicians and hospitals with a tool to evaluate risk-adjusted outcomes and to guide quality improvement. The Society of Thoracic Surgeons (STS) Predicted Risk of Mortality (PROM) is the most commonly used risk algorithm, others being the EuroSCORE logistic and additive algorithm and the Ambler Risk Score. These models utilize pre-operative patient characteristics to predict operative risk and early outcomes. Although a great deal of effort has gone into models to predict short-term patient outcomes after common cardiac operations, there has been relatively little effort to develop a statistical algorithm to predict long-term outcomes. Moreover, no risk model takes into account early post-operative complications to construct an algorithm to predict long-term outcomes. The formulation of a risk stratification score based on post-operative complications following common cardiac surgical procedures may be used to estimate the likelihood of long-term survival for individual complications, as well as various permutations and combinations of complications. This may have profound implications in devising strategies to prevent the most devastating combination of complications. Also, this may assist in informing patients and families of the predicted survival after a particular complication or a combination of complications. As Dokollari et all pointed out, there is impetus towards the direction of formulating a risk stratification score, and this may indeed be the need of the hour.