Pulmonary nodule malignancy probability: a diagnostic accuracy meta-analysis of the Mayo model.

AIM: To quantify the overall diagnostic accuracy of the Mayo model in predicting the probability of malignancy of solitary pulmonary nodules (SPNs) by carrying out a systematic review and meta-analysis. MATERIALS AND METHODS: PubMed, Scopus, and references of relevant articles were searched systematically from inception up to 21 September 2021, to identify observational cohort studies, which reported on the diagnostic accuracy of the Mayo model in predicting the probability of malignancy in SPNs. The primary outcome was the pooled area under the receiver operating characteristic (ROC) curve (AUC). Secondary outcomes were sensitivity, specificity, and diagnostic odds ratio (DOR). The meta-analysis was registered with PROSPERO. RESULTS: Forty studies involving 46,694 patients were included. The overall pooled AUC was 0.730 (95% confidence interval [CI]: 0.704-0.755), while sensitivity and specificity were 0.78 (95% CI: 0.67-0.86) and 0.68 (95% CI: 0.57-0.77), respectively. Subgroup analyses revealed that the model had a better performance among datasets with increased prevalence of current/ex-smokers (AUC 0.762, 95% CI: 0.713-0.810, versus AUC 0.695, 95% CI: 0.660-0.730 and among studies conducted in continents other than Asia (AUC 0.769, 95% CI: 0.732-0.806 versus AUC 0.699, 95% CI: 0.669-0.729, p<0.001, I2=91.20%) CONCLUSIONS: The Mayo model seems a fair diagnostic tool; however, the synthesised evidence informs clinicians and researchers that it may be more applicable on certain patient populations, such as smokers and non-Asians.

Protein concentration and mitochondrial content in the gastrocnemius predicts mortality rates in patients with peripheral arterial disease.

OBJECTIVE: This study evaluated the hypothesis that protein concentration and mitochondrial content in gastrocnemius biopsies from patients with peripheral arterial disease (PAD) predict mortality rates. BACKGROUND: PAD patients experience advancing myopathy characterized by mitochondrial dysfunction, myofiber degradation, and fibrosis in their ischemic legs, along with increased mortality rates. METHODS: Samples from the gastrocnemius of PAD patients were used for all analyses. Protein concentration was normalized to muscle wet weight, and citrate synthase activity (standard measure of mitochondrial content in cells) was normalized to muscle wet weight and protein concentration. Protein and citrate synthase data were grouped into tertiles and 5-year, all-cause mortality for each tertile was determined with Kaplan-Meier curves and compared by the modified Peto-Peto test. A Cox-regression model for each variable controlled for the effects of clinical characteristics. RESULTS: Of the 187 study participants, 46 died during a mean follow-up of 23.0 months. Five-year mortality rate was highest for patients in the lowest tertile of protein concentration. Mortality was lowest for patients in the middle tertile of citrate synthase activity when normalized to either muscle wet weight or protein concentration. The mortality hazard ratios (HRs) from the Cox analysis were statistically significant for protein concentration normalized to muscle wet weight (lowest vs middle tertile; HR = 2.93; P = 0.008) and citrate synthase normalized to protein concentration (lowest vs middle tertile; HR = 4.68; P = 0.003; and lowest vs highest tertile; HR = 2.36; P = 0.027). CONCLUSIONS: Survival analysis of a contemporaneous population of PAD patients identifies protein and mitochondrial content of their gastrocnemius as predictors of mortality rate.