Coronary Artery Calcification and High-Volume Physical Activity: Role of Lower Intensity versus Longer Duration of Exercise.

AIM: While high-volume physical activity (PA) has been linked to elevated coronary artery calcification (CAC), the role of intensity versus duration of PA has not been investigated. The purpose of the study was to examine the role of intensity versus duration of PA in relation to CAC. METHODS: Data are from 23,383 apparently healthy men who completed a PA questionnaire and underwent CAC scanning as part of a preventive exam. Self-reported PA was categorized into 4 groups of average intensity and weekly duration of PA and (average intensity: 1, 3-5.9, 6-8.9, and 9-12 metabolic equivalents of task [METs]; weekly duration: 0, > 0-<2, 2-<5, and ≥5 hours/week). Mean CAC and CAC ≥ 100 Agatston Units (AU) were regressed separately on continuous or categorical average intensity and weekly duration of PA. RESULTS: The mean and standard deviation (SD) age was 51.7 (8.3) years, and mean CAC was 174.8 (543.6) AU with 23.5% of men presenting with CAC ≥ 100 AU. Higher average intensity of PA was related to lower mean CAC (-3.1%/MET, 95% confidence interval [CI]: -4.6, -1.6%/MET) and lower relative risk (RR) of CAC ≥ 100 AU (RR: 0.99, 95% CI: 0.98, 1.00/MET). Opposite trend was observed for the duration component wherein higher weekly duration of PA was significantly associated with greater mean CAC and RR of CAC ≥ 100 AU. CONCLUSIONS: Elevated CAC was associated with lower average intensity and longer duration of PA in men, providing new insight into the complex relationship between leisure-time PA behaviors and risk of CAC.

Does greater extent of coronary artery calcification observed at high volumes of leisure time physical activity relate more to the intensity or the duration of the activity? Higher average intensity of activity is associated with less coronary artery calcification at any age and weekly duration of activity.Higher weekly duration of activity is associated with more coronary artery calcification at any age and average intensity of activity.

Associations of ambulatory blood pressure measurements with high-sensitivity troponin and natriuretic peptide levels in SPRINT.

BACKGROUND: Nighttime blood pressure (BP) has greater prognostic importance for cardiovascular disease (CVD) than daytime BP, but less is known about nighttime and daytime BP associations with measures of subclinical CVD. METHODS: Among 897 Systolic Blood Pressure Intervention Trial Study (SPRINT) participants with 24-hour ambulatory BP monitoring obtained near the 27-month study visit, 849 (95%) had N-terminal pro-B-type natriuretic peptide (NT-proBNP) and high-sensitivity cardiac troponin T (hs-cTnT) measured at the 24-month study visit. Multivariable linear regression analyses were performed to evaluate the associations of nighttime and daytime BP with cardiac biomarker levels. RESULTS: Mean age was 69 ±12 years, 28% were African American, and mean nighttime and daytime SBP were 121 ±16 mm Hg and 132 ±14 mm Hg, respectively. In multivariable models, compared with the lowest tertile of nighttime systolic BP, the highest tertile was associated with 48% higher NT-proBNP levels (adjusted geometric mean ratio [GMR] = 1.48, 95% CI: 1.22, 1.79), and 19% higher hs-cTnT levels (adjusted GMR = 1.19, 95% CI: 1.07, 1.32). In contrast, the highest versus lowest tertile of daytime systolic BP was not associated with NT-proBNP (adjusted GMR = 1.09, 95% CI: 0.88, 1.34) but was associated with 16% higher hs-cTnT levels (adjusted GMR = 1.16, 95% CI: 1.04, 1.30). Similar results were observed using diastolic BP. CONCLUSION: In SPRINT, both higher nighttime and daytime BP were independently associated with higher hs-cTnT levels, but only higher nighttime BP was associated with higher NT-proBNP levels.

Intensive Blood Pressure Lowering in Individuals With Low Diastolic Blood Pressure and Elevated Troponin Levels in SPRINT.

BACKGROUND: Among individuals with hypertension and low diastolic blood pressure (DBP), the optimal BP target remains controversial due to concerns that BP lowering may reduce coronary perfusion. We determined the impact of intensive BP control among individuals with elevated systolic BP who have low DBP and elevated hs-cTnT (high-sensitivity cardiac troponin T) levels. METHODS AND RESULTS: A total of 8828 participants in SPRINT (Systolic Blood Pressure Intervention Trial) were stratified by baseline DBP. Those with low DBP (<70 mm Hg) were further stratified by elevated hs-cTnT (≥14 ng/L) at baseline. The effects of intensive versus standard BP lowering on a cardiovascular disease composite end point, all-cause death, and 1-year change in hs-cTnT were determined. The combination of low DBP/high hs-cTnT was independently associated with a higher risk for cardiovascular disease and all-cause death, as well as greater 1-year increases in hs-cTnT, compared with DBP ≥70 mm Hg. However, randomization to intensive versus standard BP lowering led to similar reductions in cardiovascular disease risk among individuals with low DBP/high hs-cTnT (hazard ratio [HR], 0.82 [95% CI, 0.57-1.19]), low DBP/low hs-cTnT (HR, 0.48 [95% CI, 0.29-0.79]), and DBP ≥70 mm Hg (HR, 0.73 [95% CI, 0.60-0.89]; P for interaction=0.20). Intensive BP lowering also led to a reduction in all-cause death that was similar across groups (P for interaction=0.57). CONCLUSIONS: In this nonprespecified subgroup analysis of SPRINT, individuals with low DBP and elevated hs-cTnT, low DBP and nonelevated hs-cTnT, and DBP ≥70 mm Hg derived similar cardiovascular disease and mortality benefits from intensive BP lowering. These findings warrant confirmation in other studies.

Association between dietary phosphate intake and skeletal muscle energetics in adults without cardiovascular disease.

Highly bioavailable inorganic phosphate (Pi) is present in large quantities in the typical Western diet and represents a large fraction of total phosphate intake. Dietary Pi excess induces exercise intolerance and skeletal muscle mitochondrial dysfunction in normal mice. However, the relevance of this to humans remains unknown. The study was conducted on 13 individuals without a history of cardiopulmonary disease (46% female, 15% Black participants) enrolled in the pilot-phase of the Dallas Heart and Mind Study. Total dietary phosphate was estimated from 24-h dietary recall (ASA24). Muscle ATP synthesis was measured at rest, and phosphocreatinine (PCr) dynamics was measured during plantar flexion exercise using 7-T 31P magnetic resonance (MR) spectroscopy in the calf muscle. Correlation was assessed between dietary phosphate intake normalized to total caloric intake, resting ATP synthesis, and PCr depletion during exercise. Higher dietary phosphate intake was associated with lower resting ATP synthesis (r = -0.62, P = 0.03), and with higher levels of PCr depletion during plantar flexion exercise relative to the resting period (r = -0.72; P = 0.004). These associations remain significant after adjustment for age and estimated glomerular filtration rate (both P < 0.05). High dietary phosphate intake was also associated with lower serum Klotho levels, and Klotho levels are in turn associated with PCr depletion and higher ADP accumulation post exercise. Our study suggests that higher dietary phosphate is associated with reduced skeletal muscle mitochondrial function at rest and exercise in humans providing new insight into potential mechanisms linking the Western diet to impaired energy metabolism.NEW & NOTEWORTHY This is the first translational research study directly demonstrating the adverse effects of dietary phosphate on muscle energy metabolism in humans. Importantly, our data show that dietary phosphate is associated with impaired muscle ATP synthesis at rest and during exercise, independent of age and renal function. This is a new biologic paradigm with significant clinical dietary implications.

Circulating transthyretin and retinol binding protein 4 levels among middle-age V122I TTR carriers in the general population.

BACKGROUND: Hereditary transthyretin cardiac amyloidosis (ATTRv-CA) has a long latency phase before clinical onset, creating a need to identify subclinical disease. We hypothesized circulating transthyretin (TTR) and retinol binding protein 4 (RBP4) levels would be associated with TTR carrier status and correlated with possible evidence of subclinical ATTRv-CA. METHODS: TTR and RBP4 were measured in blood samples from V122I TTR carriers and age-, sex- and race-matched non-carrier controls (1:2 matching) among Dallas Heart Study participants (phases 1 (DHS-1) and 2 (DHS-2)). Multivariable linear regression models determined factors associated with TTR and RBP4. RESULTS: There were 40 V122I TTR carriers in DHS-1 and 54 V122I TTR carriers in DHS-2. In DHS-1 and DHS-2, TTR was lower in V122I TTR carriers (p < .001 for both), and RBP4 in DHS-2 was lower in V122I TTR carriers than non-carriers (p = .002). Among V122I TTR carriers, TTR was negatively correlated with markers of kidney function, and limb lead voltage (p < .05 for both) and TTR and RBP4 were correlated with atrial volume in DHS-2 (p < .05). CONCLUSIONS: V122I TTR carrier status is independently associated with lower TTR and RBP4 in comparison with non-carriers. These findings support the hypothesis that TTR and RBP4 may correlate with evidence of subclinical ATTRv-CA.

Association of global longitudinal strain by feature tracking cardiac magnetic resonance imaging with adverse outcomes among community-dwelling adults without cardiovascular disease: The Dallas Heart Study.

AIM: Left ventricular (LV) global longitudinal strain (GLS) may detect subtle abnormalities in myocardial contractility among individuals with normal LV ejection fraction (LVEF). However, the prognostic implications of GLS among healthy, community-dwelling adults is not well-established. METHODS AND RESULTS: Overall, 2234 community-dwelling adults (56% women, 47% Black) with LVEF ≥50% without a history of cardiovascular disease (CVD) from the Dallas Heart Study who underwent cardiac magnetic resonance (CMR) with GLS assessed by feature tracking CMR (FT-CMR) were included. The association of GLS with the risk of incident major adverse cardiovascular events (MACE; composite of incident myocardial infarction, incident heart failure [HF], hospitalization for atrial fibrillation, coronary revascularization, and all-cause death), and incident HF or death were assessed with adjusted Cox proportional hazards models. A total of 309 participants (13.8%) had MACE during a median follow-up duration of 17 years. Participants with the worst GLS (Q4) were more likely male and of the Black race with a history of tobacco use and diabetes with lower LVEF, higher LV end-diastolic volume, and higher LV mass index. Cumulative incidence of MACE was higher among participants with worse (Q4 vs. Q1) GLS (20.4% vs. 9.0%). In multivariable-adjusted Cox models that included clinical characteristics, cardiac biomarkers and baseline LVEF, worse GLS (Q4 vs. Q1) was associated with a significantly higher risk of MACE (hazard ratio [HR] 1.55, 95% confidence interval [CI] 1.07-2.24, p = 0.02) and incident HF or death (HR 1.57, 95% CI 1.03-2.38, p = 0.04). CONCLUSIONS: Impaired LV GLS assessed by FT-CMR among adults free of cardiovascular disease is associated with a higher risk of incident MACE and incident HF or death independent of cardiovascular risk factors, cardiac biomarkers and LVEF.

High-Sensitivity Cardiac Troponins I and T and Cardiovascular Outcomes: Findings from the Systolic Blood Pressure Intervention Trial (SPRINT).

BACKGROUND: Cardiac troponins are associated with adverse cardiovascular disease (CVD) outcomes. The value of high-sensitivity cardiac troponin I (hs-cTnI) independently and in concert with troponin T (hs-cTnT) in the management of hypertension has not been well studied. METHODS: We assessed the utility of hs-cTnI independently and with hs-cTnT in identifying the highest risk individuals in the Systolic Blood Pressure Intervention Trial (SPRINT). Among 8796 eligible SPRINT participants, hs-cTnI was measured at baseline and 1 year. The association of baseline level and 1-year change in hs-cTnI with CVD events and all-cause death was evaluated using adjusted Cox regression models. We further assessed the complementary value of hs-cTnI and hs-cTnT by identifying concordant and discordant categories and assessing their association with outcomes. RESULTS: hs-cTnI was positively associated with composite CVD risk [myocardial infarction, other acute coronary syndrome, stroke, or cardiovascular death: hazard ratio 1.23, 95% confidence interval 1.08-1.39 per 1-unit increase in log(troponin I)] independent of traditional risk factors, N-terminal pro-B-type natriuretic peptide, and hs-cTnT. Intensive blood pressure lowering was associated with greater absolute risk reduction (4.5% vs 1.7%) and lower number needed to treat (23 vs 59) for CVD events among those with higher baseline hs-cTnI (≥6 ng/L in men, ≥4 ng/L in women). hs-cTnI increase at 1 year was also associated with increased CVD risk. hs-cTnI and hs-cTnT were complementary, and elevations in both identified individuals with the highest risk for CVD and death. CONCLUSIONS: Baseline levels and change in hs-cTnI over 1 year identified higher-risk individuals who may derive greater cardiovascular benefit with intensive blood pressure treatment. hs-TnI and hs-TnT have complementary value in CVD risk assessment. ClinicalTrials.gov Registration Number: NCT01206062.

Independent and joint associations of cardiorespiratory fitness and BMI with dementia risk: the Cooper Center Longitudinal Study.

OBJECTIVE: This study aimed to examine the association of midlife fitness and body mass index (BMI) with incident dementia later in life. DESIGN AND PARTICIPANTS: A cohort study of 6428 individuals (mean age 50.9±7.6 years) from the Cooper Center Longitudinal Study. MEASURES: Cardiorespiratory fitness and BMI were assessed twice (1970-1999) during visits to the Cooper Clinic, a preventive medicine clinic in Dallas, Texas. These measures were examined as continuous and categorical variables. As continuous variables, fitness and BMI were examined at baseline (averaged of two examinations) and as absolute change between exams (mean time 2.1±1.8 years). Variables were categorised: unfit versus fit and normal versus overweight/obese. Medicare claims data were used to obtain all-cause dementia incidence (1999-2009). Mean follow-up between midlife examinations and Medicare surveillance was 15.7 ((SD=6.2) years. Multivariable models were used to assess the associations between fitness, BMI and dementia. RESULTS: During 40 773 person years of Medicare surveillance, 632 cases of dementia were identified. After controlling for BMI and covariates, each 1-metabolic equivalent increment in fitness was associated with 5% lower (HR 0.95; 95% CI 0.90 to 0.99) dementia risk. In comparison, after controlling for fitness and covariates, each 1 kg/m2 increment in BMI was associated with a 3.0% (HR 1.03; 95% CI 1.00 to 1.07) higher risk for dementia, yet without significance (p=0.051). Similar findings were observed when the exposures were categorised. Changes in fitness and BMI between examinations were not related to dementia. Jointly, participants who were unfit and overweight/obese had the highest (HR 2.28 95% CI 1.57 to 3.32) dementia risk compared with their fit and normal weight counterparts. CONCLUSION: Lower midlife fitness is a risk marker for dementia irrespective of weight status. Being unfit coupled with overweight/obese status might increase one's risk for dementia even further.

Changes in Natriuretic Peptide Levels and Subsequent Kidney Function Decline in SPRINT.

RATIONALE & OBJECTIVE: Novel approaches to the assessment of kidney disease risk during hypertension treatment are needed because of the uncertainty of how intensive blood pressure (BP) lowering impacts kidney outcomes. We determined whether longitudinal N-terminal pro-B-type natriuretic peptide (NT-proBNP) measurements during hypertension treatment are associated with kidney function decline. STUDY DESIGN: Prospective observational study. SETTING & PARTICIPANTS: 8,005 SPRINT (Systolic Blood Pressure Intervention Trial) participants with NT-proBNP measurements at baseline and 1 year. EXPOSURE: 1-year change in NT-proBNP categorized as a ≥25% decrease, ≥25% increase, or <25% change (stable). OUTCOME: Annualized change in estimated glomerular filtration rate (eGFR) and ≥30% decrease in eGFR. ANALYTICAL APPROACH: Linear mixed-effect and logistic regression models were used to evaluate the association of changes in NT-proBNP with subsequent annualized change in eGFR and ≥30% decrease in eGFR, respectively. Analyses were stratified by baseline chronic kidney disease (CKD) status. RESULTS: Compared with stable 1-year NT-proBNP levels, a ≥25% decrease in NT-proBNP was associated with a slower decrease in eGFR in participants with CKD (adjusted difference, 1.09%/y; 95% CI, 0.35-1.83) and without CKD (adjusted difference, 0.51%/y; 95% CI, 0.21-0.81; P = 0.4 for interaction). Meanwhile, a ≥25% increase in NT-proBNP in participants with CKD was associated with a faster decrease in eGFR (adjusted difference, -1.04%/y; 95% CI, -1.72 to -0.36) and risk of a ≥30% decrease in eGFR (adjusted odds ratio, 1.44; 95% CI, 1.06-1.96); associations were stronger in participants with CKD than in participants without CKD (P = 0.01 and P < 0.001 for interaction, respectively). Relationships were similar irrespective of the randomized BP arm in SPRINT (P > 0.2 for interactions). LIMITATIONS: Persons with diabetes and proteinuria >1 g/d were excluded. CONCLUSIONS: Changes in NT-proBNP during BP treatment are independently associated with subsequent kidney function decline, particularly in people with CKD. Future studies should assess whether routine NT-proBNP measurements may be useful in monitoring kidney risk during hypertension treatment. PLAIN-LANGUAGE SUMMARY: N-terminal pro-B-type natriuretic peptide (NT-proBNP) is a biomarker in the blood that reflects mechanical stress on the heart. Measuring NT-proBNP may be helpful in assessing the risk of long-term losses of kidney function. In this study, we investigated the association of changes in NT-proBNP with subsequent kidney function among individuals with and without chronic kidney disease. We found that increases in NT-proBNP are associated with a faster rate of decline of kidney function, independent of baseline kidney measures. The associations were more pronounced in individuals with chronic kidney disease. Our results advance the notion of considering NT-proBNP as a dynamic tool for assessing kidney disease risk.

Association between baseline levels of muscular strength and risk of stroke in later life: The Cooper Center Longitudinal Study.

PURPOSE: Muscular strength is an important component of physical fitness. We evaluated the relationship between baseline muscular strength and risk of stroke among adults who were aged ≥65 years during follow-up. METHODS: We included 7627 healthy adults (mean age = 43.9 years, 86.0% male) underwent a baseline physical examination between 1980 and 1989. Muscular strength was determined by 1-repetition maximum measures for bench press and leg press and categorized into age- and sex-specific tertiles for each measure. Cardiorespiratory fitness (CRF) was assessed via a maximal treadmill exercise test. Those enrolled in fee-for-service Medicare from 1999 to 2019 were included in the analyses. Associations between baseline strength and stroke outcomes were estimated using a modified Cox proportional hazards model. In a secondary analysis, we examined stroke risk by categories of CRF where Quintile 1 = low, Quintiles 2-3 = moderate, and Quintiles 4-5 = high CRF based on age and sex. RESULTS: After 70,072 person-years of Medicare follow-up, there were 1211 earliest indications of incident stroke. In multivariable analyses, the hazard ratio (95% confidence interval (95%CI)) for stroke across bench press categories were 1.0 (referent), 0.96 (0.83-1.11), and 0.89 (0.77-1.04), respectively (p trend = 0.14). The trend across categories of leg press was also non-significant (p trend = 0.79). Adjusted hazard ratio (95%CI) for stroke across ordered CRF categories were 1.0 (referent), 0.90 (0.71-1.13), and 0.72 (0.57-0.92) (p trend < 0.01). CONCLUSION: While meeting public health guidelines for muscular strengthening activities is likely to improve muscular strength as well as many health outcomes in older adults, performing such activities may not be helpful in preventing stroke. Conversely, meeting guidelines for aerobic activity is likely to improve CRF and lower stroke risk.

Longitudinal Changes in Cardiac Troponin and Risk of Heart Failure Among Black Adults.

BACKGROUND: Among Black adults, high-sensitivity cardiac troponin I (hs-cTnI) is associated with heart failure (HF) risk. The association of longitudinal changes in hs-cTnI with risk of incident HF, HF with reduced and preserved ejection fraction (HFrEF and HFpEF, respectively), among Black adults is not well-established. METHODS AND RESULTS: This study included Black participants from the Jackson Heart Study with available hs-cTnI data at visits 1 (2000-2004) and 2 (2005-2008) and no history of cardiovascular disease. Cox models were used to evaluate associations of categories of longitudinal change in hs-cTnI with incident HF risk. Among 2423 participants, 11.6% had incident elevation in hs-cTnI at visit 2, and 16.9% had stable or improved elevation (≤50% increase in hs-cTnI), and 4.0% had worsened hs-cTnI elevation (>50% increase). Over a median follow-up of 12.0 years, there were 139 incident HF hospitalizations (64 HFrEF, 58 HFpEF). Compared with participants without an elevated hs-cTnI, those with incident, stable or improved, or worsened hs-cTnI elevation had higher HF risk (adjusted hazard ratio 3.20 [95% confidence interval, 1.92-5.33]; adjusted hazard ratio 2.40, [95% confidence interval, 1.47-3.92]; and adjusted hazard ratio 8.10, [95% confidence interval, 4.74-13.83], respectively). Similar patterns of association were observed for risk of HFrEF and HFpEF. CONCLUSIONS: Among Black adults, an increase in hs-cTnI levels on follow-up was associated with a higher HF risk. LAY SUMMARY: The present study included 2423 Black adults from the Jackson Heart Study with available biomarkers of cardiac injury and no history of cardiovascular disease at visits 1 and 2. The majority of participants did not have evidence of cardiac injury at both visits (67.5%), 11.6% had evidence of cardiac injury only on follow-up, 14.5% had stable elevations, 4.0% had worsened elevations, and 2.4% had improved elevations of cardiac injury biomarkers during follow-up. Compared with participants without evidence of cardiac injury, those with new, stable, and worsened levels of cardiac injury had a higher risk of developing heart failure. TWEET: Among Black adults, persistent or worsening subclinical myocardial injury is associated with an elevated risk of HF.

Associations of liver fat content with cardiometabolic phenotypes and outcomes in a multi-ethnic population: Results from the Dallas Heart Study.

AIMS: To evaluate the associations between liver fat content and cardiometabolic parameters to explore potential threshold values that define metabolically healthy liver fat content, and to examine the association of liver fat content with cardiovascular events as well as its longitudinal progression. METHODS: Participants in the Dallas Heart Study underwent clinical evaluation, including laboratory testing, and liver fat quantification by magnetic resonance spectroscopy (MRS) at baseline (N = 2287) and at follow-up (N = 343) after a mean of 7.3 years. Cardiovascular events were adjudicated (>12 years). RESULTS: The mean age at study entry was 44 years, 47% of participants were men, and 48% were African American. The following cardiometabolic biomarkers worsened across liver fat quintiles (P < 0.0001): body mass index (BMI); waist circumference; prevalence of hypertension; prevalence of diabetes; cholesterol, triglyceride, high-sensitivity C-reactive protein (CRP), leptin and fasting glucose levels; homeostatic model assessment of insulin resistance index (HOMA-IR); coronary artery calcium score; visceral adipose tissue; abdominal subcutaneous adipose tissue; and lower body subcutaneous adipose tissue. Cardiovascular events were comparable across groups defined by tertile of baseline liver fat content. Change in BMI (R = 0.40), waist circumference (R = 0.35), CRP (R = 0.31), alanine aminotransferase (R = 0.27), HOMA-IR (R = 0.26), aspartate transaminase (R = 0.15) and triglycerides (R = 0.12) significantly correlated with change in liver fat content (P < 0.01 for all). CONCLUSION: Clinically relevant metabolic abnormalities were higher across quintiles of liver fat, with increases noted well within normal liver fat ranges, but cardiovascular events were not associated with liver fat content. Longitudinal changes in metabolic parameters, especially adiposity-related parameters, were correlated with change in liver fat content.

Impact of the Insoluble Gas Concentration on Measured Stroke Volume at Rest and Submaximal Exercise Using the Innocor Device.

INTRODUCTION: The Innocor® device uses an insoluble gas (SF 6 ) to estimate lung volume and the rate of disappearance of a soluble gas (nitrous oxide) to measure pulmonary blood flow (PBF), which approximates cardiac output assuming no shunt. We sought to identify error in the measurement of the insoluble gas in an effort to reduce variation in Innocor® measurement. METHODS: We enrolled 28 participants from the Dallas Heart Study (mean age, 63 yr; 57% men; 43% White). Stroke volume was measured at rest and at submaximal (20 and 40 W) exercise using both echocardiography (Philips iE33) and the Innocor® device. We defined a priori peak and equilibrium SF 6 measurement errors as greater or less than 20% of the mean observed value. Three Innocor measurements were obtained at rest ( n = 27) for a total of 81 measurements. Of these, 22% had SF 6 measurements that fell outside of the a priori range. RESULTS: Resting Innocor® stroke volume measures with peak SF 6 measured above a priori range (>0.12%) was associated with larger stroke volumes compared with stroke volume measures without peak SF 6 error (101.4 [26.8] vs 64.9 [8.7] mL; P = 0.006) and overestimated stroke volume when compared with stroke volume by echo (101.4 [26.8] vs 59.9 [16.3] mL; P = 0.017). A similar pattern was observed at submaximal exercise. In contrast, there was no consistent association between variation in equilibrium SF 6 concentrations and measured stroke volume. CONCLUSIONS: Variability in peak SF 6 concentration is common while using the Innocor® device and results in overestimated stroke volume. These findings have implications for research protocols using this device.

Effect of Intensive Blood Pressure Control on Troponin and Natriuretic Peptide Levels: Findings From SPRINT.

BACKGROUND: Given the important role of cardiac injury and neurohormonal activation in the pathways leading from hypertension to heart failure and strong associations observed between hypertension and its sequelae on hs-cTnT (high-sensitivity cardiac troponin T) and NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels, we hypothesized that intensive systolic blood pressure (SBP) lowering would decrease levels of hs-cTnT and NT-proBNP. METHODS: hs-cTnT and NT-proBNP were measured at baseline and 1 year from stored specimens in SPRINT (Systolic Blood Pressure Intervention Trial). Changes in biomarkers were evaluated continuously on the log scale and according to categories (≥50% increase, ≥50% decrease, or <50% change). The effect of intensive SBP lowering on continuous and categorical changes in biomarker levels were assessed using linear and multinomial logistic regression models, respectively. The association between changes in biomarkers on heart failure and death was assessed using multivariable-adjusted Cox proportional hazards models. RESULTS: Randomization to intensive SBP lowering (versus standard SBP management) resulted in a 3% increase in hs-cTnT levels over 1-year follow-up (geometric mean ratio, 1.03 [95% CI, 1.01-1.04]) and a higher proportion of participants with ≥50% increase (odds ratio, 1.47 [95% CI, 1.13, 1.90]). In contrast, randomization to intensive SBP lowering led to a 10% decrease in NT-proBNP (geometric mean ratio, 0.90 [95% CI, 0.87-0.93]) and a lower probability of ≥50% increase in NT-proBNP (odds ratio, 0.57 [95% CI, 0.46-0.72]). The association of randomized treatment assignment on change in hs-cTnT was completely attenuated after accounting for changes in estimated glomerular filtration rate over follow-up, whereas the association of treatment with NT-proBNP was completely attenuated after adjusting for change in SBP. Increases in hs-cTnT and NT-proBNP from baseline to 1 year were associated with higher risk for heart failure and death, with no significant interactions by treatment assignment. CONCLUSIONS: Intensive SBP lowering increased hs-cTnT, mediated by the effect of SBP lowering on reduced kidney filtration. In contrast, intensive SBP lowering decreased NT-proBNP, a finding that was explained by the decrease in SBP. These findings highlight the importance of noncardiac factors influencing variation in cardiac biomarkers and raise questions about the potential role of hs-cTnT as a surrogate marker for heart failure or death in SBP-lowering studies.

Intensive Blood Pressure Lowering in Patients With Malignant Left Ventricular Hypertrophy.

BACKGROUND: Left ventricular hypertrophy (LVH) combined with elevations in cardiac biomarkers reflecting myocardial injury and neurohormonal stress (malignant LVH) is associated with a high risk for heart failure and death. OBJECTIVES: The aim of this study was to determine the impact of intensive systolic blood pressure (SBP) control on the prevention of malignant LVH and its consequences. METHODS: A total of 8,820 participants in SPRINT (Systolic Blood Pressure Intervention Trial) were classified into groups based on the presence or absence of LVH assessed by 12-lead ECG, and elevations in biomarker levels (high-sensitivity cardiac troponin T ≥14 ng/L or N-terminal pro-B-type natriuretic peptide ≥125 pg/mL) at baseline. The effects of intensive vs standard SBP lowering on rates of acute decompensated heart failure (ADHF) events and death and on the incidence and regression of malignant LVH were determined. RESULTS: Randomization to intensive SBP lowering led to similar relative reductions in ADHF events and death across the combined LVH/biomarker groups (P for interaction = 0.68). The absolute risk reduction over 4 years in ADHF events and death was 4.4% (95% CI: -5.2% to 13.9%) among participants with baseline malignant LVH (n = 449) and 1.2% (95% CI: 0.0%-2.5%) for those without LVH and nonelevated biomarkers (n = 4,361). Intensive SBP lowering also reduced the incidence of malignant LVH over 2 years (2.5% vs 1.1%; OR: 0.44; 95% CI: 0.30-0.63). CONCLUSIONS: Intensive SBP lowering prevented malignant LVH and may provide substantial absolute risk reduction in the composite of ADHF events and death among SPRINT participants with baseline malignant LVH.

Accelerated brain aging in individuals with diabetes: Association with poor glycemic control and increased all-cause mortality.

BACKGROUND: Diabetes has been linked to accelerated brain aging, i.e., neuroimaging-predicted age of brain is higher than chronological age. This report evaluated whether accelerated brain aging in diabetes is associated with higher levels of glycated hemoglobin (HbA1c) and increased mortality. METHODS: Brain age in Dallas Heart Study (n = 1949) was estimated using T1-weighted magnetic resonance imaging (MRI) scans and a previously-published Gaussian Processes Regression model. Accelerated brain aging (adjusted Δ brain age) was computed as follows: (brain age adjusted for chronological age)-minus-(chronological age). Mortality data until 12/31/2016 were obtained from the National Death Index. Associations of adjusted Δ brain age with diabetes in full sample and with HbA1c in individuals with diabetes were evaluated. Proportion of association between diabetes and all-cause mortality that was accounted for by adjusted Δ brain age were evaluated with mediation analyses. Covariates included Framingham 10-year risk score, race/ethnicity, income, body mass index, and history of myocardial infarction. RESULTS: Diabetes was associated with] higher adjusted Δ brain age [estimate= 1.79; 95% confidence interval (CI): 0.889, 2.68]. Among those with diabetes, higher HbA1c (log-base-2-transformed) was associated with higher adjusted Δ brain age (estimate=3.88; 95% CI: 1.47, 6.30). Over a median follow-up of 97.5 months, 24/246 (9.8%) with diabetes and 63/1703 (3.7%) without diabetes died. Adjusted Δ brain age accounted for 65.3 (95% CI: 39.3, 100.0)% of the association between diabetes and all-cause mortality. CONCLUSION: Accelerated brain aging may be related to poor glycemic control in diabetes and partly account for the association between diabetes and all-cause mortality.