The prognostic value of the Frank sign

Frank’s sign (named after American pulmonologist Sanders T. Frank) refers to a diagonal skin fold between the tragus and outer edge of the earlobe. Gradation is based on the bilateral presence and/or degree of the earlobe fold. The presence of this sign, referred to as the diagonal earlobe crease (DELC), has been associated with coronary artery disease (CAD), independent of other cardiovascular risk factors. Corresponding studies are predominantly based on clinical or angiographic assessments, and few autopsy studies exist. The association of DELC with CAD, cardiovascular risk factors, and causes of death was investigated via retrospective and prospective evaluations. It was also investigated whether the degree of DELC correlated with the macroscopic severity of coronary heart disease. Furthermore, the influence of age on the appearance of DELC was analyzed and compared using two age groups. Additionally, binomial logistic regression analysis was performed to investigate the influence of age on the presence of higher-grade DELC and CAD. In cases related to a lethal cardiac event, the majority (78%) showed high-grade DELC. The DELC grade correlated significantly with CAD severity (r(s) = 0.474, p < 0.001) and with the severity of general atherosclerosis (r(s) = 0.606, p < 0.001) with medium and large effects sizes, respectively. Age was predominantly more suitable than DELC concerning the sensitivity, specificity, and positive prognostic value for preexisting cardiac disease and cardiac-related causes of death. In both DELC and CAD, age has a significant influence on the presence of higher-grade manifestation, but the influence of age in CAD appears to be even more significant than in DELC. The main results of previous autopsy studies and the prognostic value could have been confirmed, but these findings appear to be limited to younger patients.