Cardiac Mechanics and the Risk of Atrial Fibrillation in a Community-Based Cohort of Older Adults.

BACKGROUND: Assessment of cardiac structure and function improves risk prediction of new-onset atrial fibrillation (AF) in different populations. We aimed to comprehensively compare standard and newer measures of cardiac structure and function in improving prediction of AF in a cohort of older adults without history of AF and stroke. METHODS: We included 5050 participants without prevalent AF and stroke (mean age 75 ± 5 years, 59% women and 22% Black) from the Atherosclerosis Risk in Communities (ARIC) study who underwent complete 2-dimensional echocardiography, including speckle-tracking analysis of the left ventricle (LV) and left atrium (LA). We assessed the association of cardiac measures with incident AF (including atrial flutter) and quantified the extent to which these measures improved model discrimination and risk classification of AF compared with the CHARGE-AF score. RESULTS: Over a median follow-up time of 7 years, 676 participants developed AF (incidence rate, 2.13 per 100 person-years). LV mass index and wall thickness, E/e' and measures of LA structure and function, but not LV systolic function, were associated with incident AF, after accounting for confounders. Above all, LA reservoir strain, contraction strain, and LA minimal volume index (C-statistics [95%Confidence interval]: 0.73 [0.70,0.75], 0.72 [0.70,0.75] and 0.72 [0.69,0.75], respectively) significantly improved the risk discrimination of the CHARGE-AF score (baseline C-statistic: 0.68 [0.65,0.70]) and achieved the highest category-based net reclassification improvement (29%, 24% and 20%, respectively). CONCLUSIONS: In a large cohort of older adults without prevalent AF and stroke, measures of LA function improved the prediction of AF more than other conventional cardiac measures.

Temporal Changes in Electrolytes, Acid-Base, QTc Duration, and Point-of-Care Ultrasound during Inpatient Hemodialysis Sessions.

Background: Of the more than 550,000 patients receiving maintenance hemodialysis (HD) in the United States, each has an average of 1.6 admissions annually (>880,000 inpatient HD sessions). Little is known about the temporal changes in laboratory values, ECGs, and intravascular and extravascular volume during inpatient HD sessions. Methods: In this prospective cohort study of hospitalized HD patients, we assessed intradialytic laboratory values (metabolic panels, blood gases, ionized calcium levels), ECGs, and sonographic measures of volume status. Results: Among 30 participants undergoing HD (mean age 62 years; 53% men, 43% Black) laboratory values had the largest changes in the first hour of HD. There was no significant change in ionized calcium levels pre- to post-HD (change: -0.01±0.07, P=0.24); 12 of 30 and 17 of 30 patients had levels below the lower reference limit at the beginning and end of HD, respectively. The mean pH increased pre- to post-HD (change: 0.06±0.04, P<0.001); 21 of 30 had a pH above the upper reference limit post-HD. There was a trend toward longer median QTc duration from pre- to post-HD (change: 7.5 msec [-5 msec, 19 msec], P=0.07). The sum of B lines on lung ultrasound decreased from pre- to post-HD (median decrease: 3 [1, 7], P<0.01). The collapsibility index of the inferior vena cava increased pre- to post-HD (median increase: 4.8% [1.5%, 13.4%], P=0.01), whereas internal jugular vein diameter did not change (P=0.24). Conclusions: Among hospitalized patients undergoing HD, we found dynamic changes in laboratory values, QTc duration, and volume status. Further research is required to assess whether HD prescriptions can be tailored to alter these variations to potentially improve patient outcomes.

Association of Left Atrial Structure and Function With Heart Failure in Older Adults.

BACKGROUND: Limited data exist to characterize novel measures of left atrial (LA) structure and function in older adults without prevalent heart failure (HF). OBJECTIVES: The aim was to assess reference range of LA measures, their associations with N-terminal pro-B-type natriuretic-peptide (NT-proBNP) and the related risk for incident HF or death. METHODS: We analyzed LA structure (LA maximal [LAViMax] and minimal volume indexed by body surface area) and function (LA emptying fraction, LA reservoir, conduit, and contraction strain) in 4,901 participants from the ARIC (Atherosclerosis Risk In Communities) study (mean age 75 ± 5 years, 40% male, and 19% Black) without prevalent HF. We assessed sex-specific 10th and 90th percentile ARIC-based reference limits in 301 participants free of prevalent cardiovascular disease, and related LA measures to NT-proBNP and incident HF or death (median follow-up of 5.5 years) in the whole ARIC cohort. RESULTS: Approximately 20% of the overall population had LA abnormalities according to the ARIC-based reference limit. Each LA measure was associated with NT-proBNP and, except for LAViMax, with incident HF or death after multivariable adjustment (including left ventricular function and NT-proBNP). Results were consistent in participants with normal LAViMax (P for interaction > 0.05). LA measures were prognostic for both incident HF with preserved ejection fraction or death and incident HF with reduced ejection fraction or death. When added to HF risk factors and NT-proBNP (baseline C-statistics = 0.74) all LA measures, except for LAViMax, significantly enhanced the prognostic accuracy. CONCLUSIONS: Novel measures of LA structure and function, but not standard assessment by LAViMax, are associated with increased risk of incident HF or death regardless of measures of left ventricular function and NT-proBNP.

Haemodynamic effects of the nitroxyl donor cimlanod (BMS-986231) in chronic heart failure: a randomized trial.

AIMS: Nitroxyl provokes vasodilatation and inotropic and lusitropic effects in animals via post-translational modification of thiols. We aimed to compare effects of the nitroxyl donor cimlanod (BMS-986231) with those of nitroglycerin (NTG) or placebo on cardiac function in patients with chronic heart failure with reduced ejection fraction (HFrEF). METHODS AND RESULTS: In a randomized, multicentre, double-blind, crossover trial, 45 patients with stable HFrEF were given a 5 h intravenous infusion of cimlanod, NTG, or placebo on separate days. Echocardiograms were done at the start and end of each infusion period and read in a core laboratory. The primary endpoint was stroke volume index derived from the left ventricular outflow tract at the end of each infusion period. Stroke volume index with placebo was 30 ± 7 mL/m2 and was lower with cimlanod (29 ± 9 mL/m2 ; P = 0.03) and NTG (28 ± 8 mL/m2 ; P = 0.02). Transmitral E-wave Doppler velocity on cimlanod or NTG was lower than on placebo and, consequently, E/e' (P = 0.006) and E/A ratio (P = 0.003) were also lower. NTG had similar effects to cimlanod on these measurements. Blood pressure reduction was similar with cimlanod and NTG and greater than with placebo. CONCLUSION: In patients with chronic HFrEF, the haemodynamic effects of cimlanod and NTG are similar. The effects of cimlanod may be explained by venodilatation and preload reduction without additional inotropic or lusitropic effects. Ongoing trials of cimlanod will further define its potential role in the treatment of heart failure.