Left atrial function measured by cardiac magnetic resonance imaging in patients with heart failure: clinical associations and prognostic value.

BACKGROUND: Left atrial (LA) volume is an important marker of cardiac dysfunction and cardiovascular outcome in heart failure (HF), but LA function is rarely measured. METHODS: Left atrial emptying function (LAEF), its clinical associations and prognostic value was studied in outpatients referred with suspected HF who were in sinus rhythm and had cardiac magnetic resonance imaging (CMRI). Heart failure was defined as relevant symptoms and signs with either a left ventricular ejection fraction (LVEF) <50% or amino-terminal pro-B-type natriuretic peptide (NTproBNP) >400 pg/mL (or >125 pg/mL if taking loop diuretics). RESULTS: Of 982 patients, 664 fulfilled the HF criteria and were in sinus rhythm. The median (interquartile range, IQR) LAEF was 42 (31-51)% and 55 (48-61)% in patients with and without HF (P < 0.001). Patients with HF in the lowest quartile of LAEF (23%; IQR: 17-28%) had lower LV and right ventricular (RV) EF, and greater LV and RV mass and higher plasma NTproBNP than those in the highest quartile of LAEF (56%; IQR: 53-61%). Log[LAEF] and log[NTproBNP] were inversely correlated (r = -0.410, P < 0.001). During a median follow-up of 883 (IQR: 469-1626) days, 394 (59%) patients with HF died or were admitted with HF and 101 (15%) developed atrial fibrillation (AF). In a multivariable Cox model, increasing LAEF, but not LVEF, was independently associated with survival (HR for 10% change: 0.81 (95%CI: 0.73-0.90), P = <0.001). Increasing age and decreasing LAEF predicted incident AF. CONCLUSIONS: In patients with HF, LAEF predicts adverse outcome independently of other measures of cardiac dysfunction.

Clinical and prognostic relationships of pulmonary artery to aorta diameter ratio in patients with heart failure: a cardiac magnetic resonance imaging study.

BACKGROUND: The pulmonary artery (PA) distends as pressure increases. HYPOTHESIS: The ratio of PA to aortic (Ao) diameter may be an indicator of pulmonary hypertension and consequently carry prognostic information in patients with chronic heart failure (HF). METHODS: Patients with chronic HF and control subjects undergoing cardiac magnetic resonance imaging were evaluated. The main PA diameter and the transverse axial Ao diameter at the level of bifurcation of the main PA were measured. The maximum diameter of both vessels was measured throughout the cardiac cycle and the PA/Ao ratio was calculated. RESULTS: A total of 384 patients (mean age, 69 years; mean left ventricular ejection fraction, 40%; median NT-proBNP, 1010 ng/L [interquartile range, 448-2262 ng/L]) and 38 controls were included. Controls and patients with chronic HF had similar maximum Ao and PA diameters and PA/Ao ratio. During a median follow-up of 1759 days (interquartile range, 998-2269 days), 181 patients with HF were hospitalized for HF or died. Neither PA diameter nor PA/Ao ratio predicted outcome in univariable analysis. In a multivariable model, only age and NT-proBNP were independent predictors of adverse events. CONCLUSIONS: The PA/Ao ratio is not a useful method to stratify prognosis in patients with HF.

Tachycardia-induced cardiomyopathy in pregnancy.

Heart failure in pregnancy is rare, but usually ascribed to peripartum cardiomyopathy in the absence of other possible diagnoses. However, heart failure can develop solely due to a tachycardia, so-called 'tachycardia-induced cardiomyopathy'. The incidence of tachycardia-induced cardiomyopathy in pregnancy is unknown, but it is a treatable and potentially reversible cause of heart failure. Clinically, tachycardia-induced cardiomyopathy during pregnancy might present in a similar manner, but its management has to be individualized according to the arrhythmic substrate and usually involve multidisciplinary input from specialists in obstetrics, cardiac electrophysiology and heart failure.

The relationship of QRS morphology with cardiac structure and function in patients with heart failure.

INTRODUCTION: The relationship of QRS morphology with cardiac structure and function in patients with heart failure is uncertain. METHODS: Patients with a clinical diagnosis of heart failure and objective evidence of cardiac dysfunction [either a left ventricular ejection fraction (LVEF) <50 % or an amino-terminal pro-brain natriuretic peptide (NT-proBNP) ≥400 pg/ml] who had been investigated by cardiac magnetic resonance imaging (CMRI) were identified. QRS duration ≥120 ms was grouped morphologically as left (LBBB), right bundle branch block (RBBB) or indeterminate. RESULTS: Of 877 patients, 320 (36 %) had QRS ≥ 120 ms. Compared to patients with LBBB, those with RBBB had a lower median [inter-quartile range (IQR)] right ventricular (RV) ejection fraction [RBBB: 46 (37-57); LBBB: 52 (42-61) %; p = 0.014], greater median (IQR) RV mass [RBBB: 53 (42-73); LBBB: 45 (36-56) g; p < 0.001], higher median (IQR) plasma NT-proBNP [RBBB: 2013 (659-3573); LBBB: 1159 (589-2207) pg/ml, p = 0.026], more signs of peripheral congestion and higher prevalence of atrial fibrillation but had similar LVEF. During a median follow-up of 1302 days (IQR: 742-2237), 311 patients died. Compared with patients who had QRS < 120 ms, those with RBBB [HR 1.98, 95 % CI (1.37-2.86); p < 0.001] had a higher mortality. Age and NT-proBNP were the strongest independent predictors of mortality; neither QRS nor CMRI variables improved prediction. CONCLUSIONS: In patients with heart failure and QRS ≥ 120 ms, RBBB is associated with more severe RV dysfunction and congestion and a worse prognosis. However, neither QRS morphology nor CMRI data provide independent prognostic information in a multivariable analysis including NT-proBNP.

Old and newer biomarkers in heart failure: from pathophysiology to clinical significance.

Heart failure is a complex disease in which a careful clinical examination and the measurement of cardiac function may not always be sufficient for making a correct diagnosis. Measuring plasma levels of natriuretic peptides may assist in this process, also offering a good tool for accurate risk stratification. Other alternative biomarkers may give insight into the different pathways of heart failure genesis and pathophysiology, and may help to identify those patients with overt heart failure and a more adverse outcome, or distinguish between those at risk of developing heart failure. Despite a high number of potentially useful biomarkers, only a few will likely be introduced routinely into clinical practice. However, a multi-marker approach might increase the diagnostic accuracy and it might identify different phenotypes of heart failure patients who might benefit from individualized therapy in the future.