Racial/ethnic differences in the prognostic utility of left ventricular mass index for incident cardiovascular disease

Age-dependent implications of left ventricular hypertrophy regression in patients with hypertension

Left ventricular hypertrophy (LVH) is a significant risk factor for cardiovascular mortality and morbidity in patients with hypertension. However, the effect of age on LVH regression or persistence and its differential prognostic value remain unclear. Therefore, we investigated the clinical implications of LVH regression in 1847 patients with hypertension and echocardiography data (at baseline and during antihypertensive treatment at an interval of 6-18 months) according to age. LVH was defined as a left ventricular mass index (LVMI) > 115 g/m2 and >95 g/m2 in men and women, respectively. LVH prevalence at baseline was not different according to age (age < 65 years: 42.6%; age ≥65 years: 45.7%; p = 0.187), but LVH regression was more frequently observed in the younger group (36.4% vs. 27.5%; p = 0.008). Spline curves and multiple linear regression analysis showed a significant relationship between reductions in systolic blood pressure and LVMI in the younger group (β = 0.425; p < 0.001), but not the elderly group (β = 0.044; p = 0.308). LVH regression was associated with a lower risk of the study outcome (composite of cardiovascular death and hospitalization for heart failure) regardless of age. In conclusion, the association between the reduction in blood pressure and LVH regression was prominent in patients with age < 65 years, but not in those with age ≥65 years. However, an association between LVH regression and lower risk of cardiovascular death and hospitalization for heart failure was observed regardless of patient age, suggesting the prognostic value of the LVH regression not only in the younger patients but also in elderly patients.

Association between clustering of cardiovascular risk factors and left ventricular geometric remodeling in Chinese children

Background

Several cardiovascular (CV) risk factors are reported to be associated with abnormal cardiac structure in children and adults. However, no study has assessed the association between clustering of multiple CV risk factors and left ventricular geometric (LVG) remodeling. We examined the association between clustering of CV risk factors and LVG remodeling among Chinese children.

Methods

This cross-sectional study included 1,406 children aged 6-11 years. Clustering of CV risk factors was quantified as the sum of the number of five CV risk factors (abdominal obesity, elevated blood pressure, high fasting blood glucose, high triglycerides and low high-density lipoprotein cholesterol). Based on left ventricular mass index and relative wall thickness (RWT), left ventricular hypertrophy (LVH), high RWT and LVG remodeling [concentric remodeling (CR), eccentric hypertrophy (EH) and concentric hypertrophy (CH)] were defined.

Results

Compared to participants without CV risk factor, those with 1, 2 and ≥3 risk factors were at increased risk of LVH [ORs (95% CIs): 3.49 (2.19-5.56), 5.53 (3.20-9.55), and 19.19 (9.67-38.08), respectively]; corresponding values for high RWT were 2.47 (1.63-3.74), 3.76 (2.25-6.27), and 5.47 (2.65-11.28). Similar associations between clustering of CV risk factors and LVG remodeling were found [CR: 1.71 (1.06-2.76), 2.83 (1.54-5.18), and 3.82 (1.37-10.62); EH: 2.42 (1.42-4.11), 4.23 (2.24-7.96), and 16.86 (7.70-36.92); CH: 14.92 (4.41-50.47), 23.15 (6.32-84.83), and 71.19 (17.09-296.56)].

Conclusion

CV risk factors in isolation and combination were associated with an increased risk of LVH, high RWT and LVG remodeling among children, emphasizing the need to consider multiple risk factors when assessing the risk of cardiac outcomes.

Development of a nomogram for screening the risk of left ventricular hypertrophy in Chinese hypertensive patients

Left ventricular hypertrophy (LVH) is an important risk factor for cardiovascular morbidity and mortality in hypertensives. Therefore, early identification of at-risk patients is necessary. The objective of this study was to estimate the risk of LVH among Chinese hypertensives by designing a nomogram. 832 hypertensives were divided into two groups based on the presence of LVH. The least absolute shrinkage and selection operator (LASSO) regression and multivariable logistic regression were successively applied for optimal variable selection and nomogram construction. Discrimination power, calibration, and clinical usefulness were evaluated using the receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis. Internal validation was performed using the bootstrap method. The nomogram included five predictors, namely gender, duration of hypertension, age, body mass index (BMI), and systolic blood pressure. The area under the ROC curve (AUC) was 0.724 (95% CI: 0.687-0.761), indicating moderate discrimination. The calibration curve showed an excellent agreement between the predicted LVH and the actual LVH probability. The risk threshold between 5% and 72% according to the decision curve analysis, and the nomogram is clinically beneficial. Internal validation by bootstrapping with 1000 samples showed a good C-index of 0.715, which suggested that the predictive abilities for the training set and testing set were in consistency. Our study proposed a nomogram that can be utilized to assess the LVH risk rapidly for Chinese hypertensives. This tool could be useful in identifying patients at high risk for LVH. Further studies are required to ascertain the stability and applicability of this nomogram.

Variation in left ventricular cardiac magnetic resonance normal reference ranges: systematic review and meta-analysis

AIMS

To determine population-related and technical sources of variation in cardiac magnetic resonance (CMR) reference ranges for left ventricular (LV) quantification through a formal systematic review and meta-analysis.

METHODS AND RESULTS

This study is registered with the International Prospective Register of Systematic Reviews (CRD42019147161). Relevant studies were identified through electronic searches and assessed by two independent reviewers based on predefined criteria. Fifteen studies comprising 2132 women and 1890 men aged 20-91 years are included in the analysis. Pooled LV reference ranges calculated using random effects meta-analysis with inverse variance weighting revealed significant differences by age, sex, and ethnicity. Men had larger LV volumes and higher LV mass than women [LV end-diastolic volume (mean difference = 6.1 mL/m2, P-value = 0.014), LV end-systolic volume (MD = 4 mL/m2, P-value = 0.033), LV mass (mean difference = 12 g/m2, P-value = 7.8 × 10-9)]. Younger individuals had larger LV end-diastolic volumes than older ages (20-40 years vs. ≥65 years: women MD = 14.0 mL/m2, men MD = 14.7 mL/m2). East Asians (Chinese, Korean, Singaporean-Chinese, n = 514) had lower LV mass than Caucasians (women: MD = 6.4 g/m2, P-value = 0.016; men: MD = 9.8 g/m2, P-value = 6.7 × 10-5). Between-study heterogeneity was high for all LV parameters despite stratification by population-related factors. Sensitivity analyses identified differences in contouring methodology, magnet strength, and post-processing software as potential sources of heterogeneity.

CONCLUSION

There is significant variation between CMR normal reference ranges due to multiple population-related and technical factors. Whilst there is need for population-stratified reference ranges, limited sample sizes and technical heterogeneity precludes derivation of meaningful unified ranges from existing reports. Wider representation of different populations and standardization of image analysis is urgently needed to establish such reference distributions.

Ethnic differences in coronary anatomy, left ventricular mass and CT-derived fractional flow reserve

BACKGROUND

Studies have observed higher incidence of cardiovascular mortality in South Asians (SA), and lower prevalence in East Asians (EA), compared with Caucasians. These observations are not entirely explained by ethnic differences in cardiovascular risk factors and mechanistic factors such as variations in cardiac anatomy and physiology may play a role. This study compared ethnic differences in CT-assessed left ventricular (LV) mass, coronary anatomy and non-invasive fractional flow reserve (FFR_CT).

METHODS

Three-hundred symptomatic patients (age 59 ± 7.9, male 51%) underwent clinically-mandated CT-coronary-angiography (CTA) were matched for age, gender, BMI and diabetes (100 each ethnicity). Assessment of coronary stenosis, luminal dimensions and vessel dominance was performed by independent observers. LV mass, coronary luminal volume and FFR_CT were quantified by blinded core-laboratory. A sub-analysis was performed on patients (n = 187) with normal/minimal disease (0-25% stenosis).

RESULTS

Stenosis severity was comparable across ethnic groups. EA demonstrated less left-dominant circulation (2%) compared with SA (8.2%) and Caucasians (10.1%). SA compared with EA and Caucasians demonstrated smallest indexed LV mass, coronary luminal volumes and dimensions. EA compared with Caucasians had comparable indexed LV mass, coronary luminal dimensions and highest luminal volumes. The latter was driven by higher prevalence of right-dominance including larger and longer right posterior left ventricular artery. FFR_CT in the left anterior descending artery (LAD) was lowest in SA (0.87) compared with EA (0.89; P = 0.009) and Caucasians (0.89; P < 0.001), with no difference in other vessels. All observed differences were consistent in patients with minimal disease.

CONCLUSION

This single-centre study identified significant ethnic differences in CT-assessed LV mass, coronary anatomy and LAD FFR_CT. These hypotheses generating results may provide a mechanistic explanation for ethnic differences in cardiovascular outcomes and require validation in larger cohorts.

Association between plasma fibroblast growth factor 23 and left ventricular mass index in patients with Takayasu arteritis

INTRODUCTION/OBJECTIVES

Fibroblast growth factor (FGF23) is an endocrine hormone that can be induced by inflammation and plays a role in the pathogenesis of cardiac abnormalities. Few studies have reported plasma FGF23 levels in patients with Takayasu arteritis (TAK). We hypothesized that the production of FGF23 in TAK is associated with abnormal cardiac mass.

METHOD

Forty-seven patients diagnosed with TAK and 52 age- and gender-matched healthy controls were included in this observational study. Plasma FGF23 was detected by human enzyme-linked immunosorbent assay. Multivariable linear regression analyses were performed to examine the association between FGF23 and left ventricular mass index (LVMI).

RESULTS

Patients with TAK had higher plasma FGF23 than healthy controls [121.8 (84.5-168.8) vs. 86.7 (70.5-101.1) RU/ml, P < 0.001]. Patients with higher FGF23 concentrations were more likely to be females (100.0% vs. 75.0%, P = 0.01), angiographic type V (69.6% vs. 33.3%, P = 0.013), heart failure (43.5% vs. 12.5%, P = 0.018), and have higher LVMI [126.3 (81.1-177.7) vs. 85.9 (69.7-114.3) g/m², P = 0.041]. Plasma FGF23 was significantly associated with LVMI in TAK patients [β = 0.402, 95% confidence interval (CI) 0.032-0.301, P = 0.016], after adjusting for age, gender, disease duration, angiographic type (angiographic type V vs. non-angiographic type V), the presence of cardiovascular events and hypertension, and serum N-terminal pro-B-type natriuretic peptide in the multivariate linear regression. Age (β = - 0.399, P = 0.016) and the presence of angiographic type V (β = 0.376, P = 0.018) were identified to be significant determinants of plasma FGF23 in patients with TAK.

CONCLUSIONS

Plasma FGF23 was elevated in patients with TAK and was associated with LVMI. FGF23 may participate in the development of abnormal cardiac mass in patients with TAK.Key Points• Plasma FGF23 was elevated in patients with TAK.• FGF23 was significantly associated with LVMI in TAK.• Age and the presence of angiographic type V were determinants of plasma FGF23 in patients with TAK.

Superiority of Out-of-Office Blood Pressure for Predicting Hypertensive Heart Disease in Non-Hispanic Black Adults

Black Americans suffer disproportionately from hypertension and hypertensive heart disease. Out-of-office blood pressure (BP) is more predictive for cardiovascular complications than clinic BP; however, the relative abilities of clinic and out-of-office BP to predict left ventricular hypertrophy in black and white adults have not been established. Thus, we aimed to compare associations of out-of-office and clinic BP measurement with left ventricular hypertrophy by cardiac magnetic resonance imaging among non-Hispanic black and white adults. In this cross-sectional study, 1262 black and 927 white participants of the Dallas Heart Study ages 30 to 64 years underwent assessment of standardized clinic and out-of-office (research staff-obtained) BP and left ventricular mass index. In multivariable-adjusted analyses of treated and untreated participants, out-of-office BP was a stronger determinant of left ventricular hypertrophy than clinic BP (odds ratio per 10 mm Hg, 1.48; 95% CI, 1.34-1.64 for out-of-office systolic BP and 1.15 [1.04-1.28] for clinic systolic BP; 1.71 [1.43-2.05] for out-of-office diastolic BP, and 1.03 [0.86-1.24] for clinic diastolic BP). Non-Hispanic black race/ethnicity, treatment status, and lower left ventricular ejection fraction were also independent determinants of hypertrophy. Among treated Blacks, the differential association between out-of-office and clinic BP with hypertrophy was more pronounced than in treated white or untreated participants. In conclusion, protocol-driven supervised out-of-office BP monitoring provides important information that cannot be gleaned from clinic BP assessment alone. Our results underscore the importance of hypertension management programs outside the medical office to prevent hypertensive heart disease, especially in high-risk black adults. Clinical Trial Registration- URL: https://www.clinicaltrials.gov. Unique identifier: NCT00344903.

Racial/ethnic differences in the prognostic utility of left ventricular mass index for incident cardiovascular disease

BACKGROUND

Evidence exists for racial/ethnic differences in left ventricular mass index (LVMI). How this translates to future cardiovascular disease (CVD) events is unknown.

HYPOTHESIS

The impact of racial/ethnic differences in LVMI on incident cardiovascular outcomes could have potential implications for the optimization of risk stratification strategies.

METHODS

Using the prospectively collected database of the Multi-Ethnic Study of Atherosclerosis (MESA) involving 4 racial/ethnic groups (non-Hispanic Whites, Chinese, Blacks, and Hispanics) free of CVD at baseline, we assessed for racial/ethnic differences in the relationship between LVMI and incident CVD using a Cox model.

RESULTS

5004 participants (mean age, 62 ± 10 years; 48% male) were included in this study. After an average follow-up of 10.2 years, 369 (7.4%) CVD events occurred. Significant racial/ethnic differences existed in the relationship between LVMI and incident CVD (P for interaction = 0.04). Notably, the relationship was strongest for Chinese (HR per 10-unit increase in LVMI: 1.7, 95% CI: 1.1-2.8) and Hispanics (HR per 10-unit increase in LVMI: 1.9, 95% CI: 1.5-2.2). Non-Hispanic Whites demonstrated the lowest relationship (HR: 1.3, 95% CI: 1.1-1.5). LVMI values of 36.9 g/m^2.7 , 31.8 g/m^2.7 , 39.9 g/m^2.7 , and 41.7 g/m^2.7 were identified as optimal cutpoints for defining left ventricular hypertrophy (LVH) for non-Hispanic Whites, Chinese, Blacks, and Hispanics, respectively. In secondary analysis of LVH (vs no LVH) using these optimal cutpoints, we found a similar pattern of association as above (P for interaction = 0.04). For example, compared with those without LVH, Chinese with LVH had HR: 5.3, 95% CI: 1.6-17, whereas non-Hispanic Whites with LVH had HR: 1.6, 95% CI: 1.2-2.1 for CVD events.

CONCLUSIONS

Among 4 races/ethnicities studied, LVMI has more prognostic utility predicting future CVD events for Chinese and Hispanics and is least significant for non-Hispanic Whites.