Untreated hypertension may contribute to increased atherosclerotic cardiovascular disease (ASCVD) risk in South Asians (SA). We assessed HTN prevalence among untreated adults free of baseline ASCVD from the MASALA & MESA studies. The proportion of participants who received discordant recommendations regarding antihypertensive pharmacotherapy use by the 2017-ACC/AHA and JNC7 Guidelines across CAC score categories in each race/ethnic group was calculated. Compared with untreated MESA participants ( n = 3896), untreated SA ( n = 445) were younger (55±8 versus 59±10 years), had higher DBP (73±10 versus 70±10 mmHg), total cholesterol (199±34 versus 196±34 mg/dL), statin use (16% versus 9%) and CAC=0 prevalence (69% versus 58%), with fewer current smokers (3% versus 15%) and lower 10-year-ASCVD-risk (6.4% versus 9.9%) (all p <0.001). A higher proportion of untreated MASALA and MESA participants were diagnosed with hypertension and recommended anti-hypertensive pharmacotherapy according to the ACC/AHA guideline compared to JNC7 (all p <0.001). Overall, discordant BP treatment recommendations were observed in 9% SA, 11% Whites, 15% Blacks, 10% Hispanics, and 9% Chinese-American. In each race/ethnic group, the proportion of participants receiving discordant recommendation increased across CAC groups (all p <0.05), however was highest among SA (40% of participants). Similar to other race/ethnicities, a higher proportion of SA are recommended anti-hypertensive pharmacotherapy by ACC/AHA as compared with JNC7 guidelines. The increase was higher among those with CAC>100 and thus may be better at informing hypertension management in American South Asians.
Untreated hypertension may contribute to the increased atherosclerotic cardiovascular disease (ASCVD) risk seen in South Asians (SA) [ , ]. We sought to estimate the change in prevalence of untreated hypertension among SA per recent and prior hypertension guidelines [ , ]. We also studied the association of coronary artery calcium (CAC) score with guideline-recommended blood-pressure (BP) categories among SA and compared with four other race/ethnic groups.
We included asymptomatic participants from two community-based cohorts: MASALA (Mediators of Atherosclerosis in South Asians Living in America) and MESA (Multi-Ethnic Study of Atherosclerosis) [ , ]. Briefly, MESA is a multi-ethnic, community-based, prospective cohort study of 6814 men and women aged 45–84 years, free from baseline clinical ASCVD. Participants were enrolled between July 2000 and September 2002 at 6 field centers in the US (Baltimore, Maryland; Chicago, Illinois; Forsyth County, North Carolina; Los Angeles County, California; New York, New York; and St. Paul, Minnesota) and identified themselves as Non-Hispanic White, African American, Hispanic, or Chinese American . MASALA is a community-based prospective cohort study of 906 asymptomatic adults, aged 40–79 years old of SA ancestry, free of known clinical ASCVD. Participants were enrolled between October 2010 and March 2013, from 2 clinical sites (University of California, San Francisco and Northwestern University . The study was approved by the institutional review boards at each center. All MASALA and MESA participants provided a written informed consent, respectively [ , ]. Per MASALA data use guidelines requiring IRB approval at an author’s home institution, IRB approval was obtained and deemed exempt from review by the Emory University IRB. Baseline data for MASALA and MESA were collected between 2010 and 2013 and 2000–2002, respectively . BP categories at which pharmacotherapy is recommended was defined according to the 2017-AHA/ACC guideline [Stage1: systolic blood-pressure (SBP) 130–139 or diastolic blood-pressure (DBP) 80–89 mmHg and clinical-ASCVD or 10-year-ASCVD-risk≥10%, Stage2: BP≥140/90 mmHg] and the Seventh Report of the Joint National Committee on Treatment of High Blood-Pressure (JNC7) (BP≥140/90 mmHg) [ , ]. Details of the CAC quantification methods implemented in each of the two studies have been reported previously [ , ]. In MESA, CAC was measured using either an electron-beam (EB) or multi-detector CT. All images were interpreted at the Los Angeles Biomedical Research Center (Torrance, CA). The intraobserver and interobserver agreement for CAC were excellent (kappa statistics, 0.93 and 0.90, respectively). In MASALA, CAC was assessed using a cardiac-gated EBCT scanner and all images were analyzed at the Los Angeles Biomedical Research Center according to MESA study methods . In both studies CAC scans were interpreted blinded to race/ethnicity and quantified using the Agatston scoring system . Both intraobserver and interobserver agreement for CAC are expected to be similar for MASALA given identical scanning protocols and imaging interpretation center.
To align with MESA, we excluded MASALA participants aged <45-years ( n = 126). We excluded participants on baseline anti-hypertensive pharmacotherapy (MASALA/MESA, n = 277/ n = 2267). We excluded participants with diabetes (DM; n = 57/ n = 364) or chronic kidney disease (CKD; n = 4/ n = 298), since both prior and current guidelines recommend similar approaches for these conditions. A considerable proportion of untreated participants with DM (54%/42%) and CKD (25%/53%) would have qualified for anti-hypertensive pharmacotherapy by both guidelines (BP≥130/80 mmHg). The untreated population consisted of 445 MASALA and 3896 MESA (1672 White, 854 Black, 884 Hispanic, and 486 Chinese-American) participants. The 10-year-ASCVD-risk was estimated using the pooled cohort equations; SA and Chinese-Americans were categorized as “other” in the PCE. The proportion of participants receiving discordant recommendations regarding anti-hypertensive pharmacotherapy use (no treatment by JNC7 [BP 120–139/80–89] and treatment by ACC/AHA [BP 130–139/80–89 with 10-year ASCVD risk >10%]) was calculated and stratified by CAC score categories (=0, 1–100, >100) in each race/ethnic group.
Compared with MESA participants, SA were younger (55±8 versus 59±10 years), had higher DBP (73±10 versus 70±10 mmHg), total cholesterol (199±34 versus 196±34 mg/dL), statin use (16% versus 9%) and CAC=0 prevalence (69% versus 58%), with fewer current smokers (3% versus 15%) and lower 10-year-ASCVD-risk (6.4% versus 9.9%) (all Mann-Whitney U [for continuous variables] and chi-square [for categorical variables] p <0.001). The prevalence of untreated hypertension across race/ethnicity is shown in Fig. 1 . A higher proportion of untreated MASALA and MESA participants were diagnosed with hypertension and recommended anti-hypertensive pharmacotherapy according to the ACC/AHA guideline compared to JNC7 (all chi-square p <0.001). Among SA, more than half qualified for lifestyle modifications and 17% were recommended anti-hypertensive pharmacotherapy by ACC/AHA compared to 8% by JNC7 (chi-square p <0.001). Overall, discordant BP treatment recommendations were observed in 9% SA, 11% Whites, 15% Blacks, 10% Hispanics, and 9% Chinese-Americans. In each race/ethnic group, the proportion of participants receiving discordant recommendation increased across CAC categories (all chi-square p <0.05, Fig. 2 ). This trend aligned with increasing ASCVD risk across CAC categories in each race/ethnic group (all p-trend<0.001).