Analysis of arterial intimal hyperplasia: review and hypothesis

which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Background: Despite a prodigious investment of funds, we cannot treat or prevent arteriosclerosis and restenosis, particularly its major pathology, arterial intimal hyperplasia. A cornerstone question lies behind all approaches to the disease: what causes the pathology? Hypothesis: I argue that the question itself is misplaced because it implies that intimal hyperplasia is a novel pathological phenomenon caused by new mechanisms. A simple inquiry into arterial morphology shows the opposite is true. The normal multi-layer cellular organization of the tunica intima is identical to that of diseased hyperplasia; it is the standard arterial system design in all placentals at least as large as rabbits, including humans. Formed initially as one-layer endothelium lining, this phenotype can either be maintained or differentiate into a normal multi-layer cellular lining, so striking in its resemblance to diseased hyperplasia that we have to name it "benign intimal hyperplasia". However, normal or "benign " intimal hyperplasia, although microscopically identical to pathology, is a controllable phenotype that rarely compromises blood supply. It is remarkable that each human heart has coronary arteries in which a single-layer endothelium differentiates earl

Climate changes and ST-elevation myocardial infarction treated with primary percutaneous coronary angioplasty

Background: The impact of seasonal changes on the incidence of acute myocardial infarction has been incompletely appraised, especially in the modern era of primary percutaneous coronary intervention (PPCI). We aimed to appraise the overall and season-specific impact of climate changes on the daily rate of PCCI.Methods: Details on PPCI and climate changes were retrospectively collected in three high-volume Italian institutions with different geographical features. The association between rate of PPCI and temperature, atmospheric pressure (ATM), humidity and rainfall was appraised with Poisson models, with overall analyses and according to season of the year.Results: Details on 6880 days with a total of 4132 PPCI were collected. Overall adjusted analysis showed that higher minimum atmospheric pressure 3 days before PPCI were associated with lower risk (regression coefficient = 0.999 [95% confidence interval 0.998-1.000], p = 0.030). Focusing on season, in Winter PPCI rates were increased by lower same day mean temperature (0.973 [0.956-0.990], p = 0.002) and lower rainfall (0.980 [0.960-1.000], p = 0.049). Conversely, in Spring greater changes in atmospheric pressure 3 days before PPCI were associated with increased risk (1.023 [1.002-1.045], p = 0.032), with similar effects in Summer for minimum temperature on the same day (1.022 [1.001-1.044], p = 0.040).Conclusions: Climate has a significant impact on the risk of PPCI in the current era, with a complex interplay according to season. Higher risk risk is expected with lower minimum atmospheric pressure in the preceding days, lower rainfall in Winter, greater changes in atmospheric pressure in Spring, and higher temperatures in Summer. These findings have important implications for prevention strategies. (C) 2019 Elsevier B.V. All rights reserved