3This study aimed to define the difference in cardiac hypertrophy between hypertensive patients with and without renal artery stenosis (RAS). When cardiac ultrasonographic examination was performed in 971 consecutive hypertensive outpatients, renal peak systolic velocity (PSV) was examined. Compared with patients without RAS, those with RAS (PSV ≥180 cm/s, 4.1%) were significantly older and included a higher proportion of male patients and had a higher left ventricular mass index (LVMI). A stratified analysis in the selected 120 patients showed that the LVMI was significantly higher in patients with RAS than in those without RAS for each confounding factor such as age and blood pressure. RAS was independently associated with a higher LVMI on propensity score analysis and multivariate analysis. Thus, the difference in LVMI between hypertensive patients with and without RAS was confirmed, irrespective of age and blood pressure, by stratified propensity score analysis and multivariate regression analysis. J Clin Hypertens (Greenwich). 2014;16:606-611. ª 2014 Wiley Periodicals, Inc.Renal artery stenosis (RAS) is found in 1% to 6% of all patients with hypertension and in 10% to 30% of hypertensive patients with known or suspected systemic atherosclerotic disease. [1][2][3][4][5] In the presence of RAS, the renin-angiotensin system is stimulated, 6 and angiotensin II has been shown to induce left ventricular hypertrophy (LVH). 7 In contrast, LVH increases the risk of systemic atherosclerotic disease such as RAS and predicts the incidence of cardiovascular events. A previous study revealed that the extent of LVH did not differ significantly between patients with renovascular hypertension and essential hypertension, 8 although the population consisted of younger patients in their 40s. Blood pressure (BP) may be a strong determinant of LVH, irrespective of the cause of hypertension. However, the prevalence of RAS is increasing because of recent advances in imaging techniques, the presence of an aging population, and an increasing prevalence of metabolic syndrome.9 At present, in this aging era, the prevalence of RAS and the differences in the extent of LVH between hypertensive populations with and without RAS and the involvement of age and BP in the differences are unclear.In a recent retrospective study, propensity scorebased analysis was performed to avoid baseline imbalances. There are 4 common techniques that use the propensity score to make adjustments for covariates before calculation of the indexed effect: (1) inverseprobability weighting, (2) matching, (3) stratification, and (4) regression adjustment. [10][11][12] The present study aimed to define the characteristics of RAS and investigate the differences in RAS-associated left ventricular mass index (LVMI) in hypertensive patients by a propensity score analysis and multivariate regression analysis. As we were interested in estimating the average effect of confounders such as age and BP on LVMI, rather than the average effect for the patients, with a greater red...