Incidence Rates of Penn Classes and Class-Specific Mortality in Acute Type A Aortic Dissection Patients: An Epidemiologic Systematic Review and Meta-Analysis

Abstract

BackgroundAcute type A aortic dissection(ATAAD) is a life-threatening emergency which is associated with a high morbidity and mortality rate. One of the complications is end-organ ischemia, a known predictor of mortality. The primary aim of this meta-analysis is to summarise the findings of observational studies investigating the utility of the Penn classification system as well as analyse the incidence rates and mortality patterns within each class. MethodsElectronic databases PubMed, MEDLINE, and Embase were searched through to April 2023. These were filtered by multiple reviewers to give ten studies that met the inclusion criteria. The extracted data included patient characteristics and primary outcomes were the incidence rates of different Penn classes, along with the corresponding mortality for each class. ResultsOut of 1512 studies identified during the initial search, ten studies met the inclusion criteria which included 4,494 patients. Pooled incidence of Penn A was highest at 0.55, 95% Confidence Interval [0.52, 0.58] followed by Penn B at 0.21 [0.17, 0.25], and finally Penn C at 0.14 [0.11, 0.17]. Patients with both Penn BC were found to be at the highest risk of death as their early mortality rates were 0.36 [0.31, 0.41]. Within those populations, the subtype with the highest individual mortality was Penn C at 0.21 [0.15, 0.27] followed by Penn B at 0.19 [0.15, 0.23] and Penn A at 0.07 [0.05, 0.10]. ConclusionAmong patients presenting with ATAAD, class A was most frequently observed, followed by classes B, C, and BC. Our findings indicate an incremental increase in mortality rates with the progression of Penn classification.