Takashi Akabane

Sympathetic Nerve Activity Efferent Drive and Beta-Blocker Treatment – Effect of Interaction in Systolic Heart Failure –

BACKGROUND Although both β-blocker dose (BBD) and sympathetic activity efferent drive are associated with prognosis in chronic heart failure (HF), little is known about the prognostic value of the interaction between them. METHODSANDRESULTS Potential prognostic variables including resting muscle sympathetic nerve activity (MSNA) were investigated in 133 patients with HF (ejection fraction [EF] <0.45). BBD was normalized to therapeutically equivalent doses of carvedilol. Primary cardiovascular endpoints included cardiovascular death and HF hospitalization. Predictors for outcomes were assessed on univariate, multivariate, and Kaplan-Meier analysis. EF was followed for 9 months after MSNA measurement in 102 patients. During the 1,419±824-day follow-up period, 24 patients died (sudden death, n=10; progressive HF, n=14). On multivariate Cox proportional hazard analysis, higher MSNA (P=0.037; HR, 2.01) and lower BBD (<5.0 mg/day; P=0.041; HR, 1.94) were independent predictors of cardiovascular events. Patients were divided into higher MSNA (≥64 bursts/100 beats) and lower MSNA groups. Although lower BBD remained an independent predictor in patients with higher MSNA, BBD was not statistically significant in patients with lower MSNA on univariate analysis. Additionally, there was a lower EF change in patients with lower BBD and higher MSNA. CONCLUSIONS Higher BBD might be necessary to avoid cardiovascular events in HF patients with central sympathetic overactivation. (Circ J 2016; 80: 2149-2154).

Restrictive Lung Function Is Related to Sympathetic Hyperactivity in Patients With Heart Failure.

BACKGROUND Sympathoexcitation and impaired lung function are common in patients with severe heart failure (HF). However, the association between impaired lung function and sympathoexcitation remains unknown. METHODS AND RESULTS Muscle sympathetic nerve activity (MSNA) and clinical variables were determined in 83 HF patients with left ventricular ejection fraction (LVEF) <0.45. Restrictive and obstructive changes on spirometry were defined as reduced forced vital capacity (FVC) of <80% of predicted and a ratio of forced expiratory volume in the first second to FVC of <70%, respectively. Restrictive and obstructive changes were identified in 17 and 21 patients, respectively. MSNA was higher in patients with restrictive changes than in those without restrictive changes (84 vs 66 bursts per 100 beats; P < .01), but was similar in those with and without obstructive changes. Univariate analyses showed that FVC, estimated glomerular filtration rate (eGFR), specific activity scale, B-type natriuretic peptide level, LVEF, age, and use of aldosterone receptor blockers were significant predictors of MSNA burst incidence. Multivariate analysis revealed that FVC, LVEF, and eGFR were independent factors for increased burst incidence. Changes in FVC during follow-up negatively correlated with changes in burst rate (n = 11; P < .01). CONCLUSION Restrictive lung function was associated with increased sympathetic nerve activity independently from HF severity.

DIFFERING EFFECTS OF ADAPTIVE SERVO-VENTILATION AND CONTINUOUS POSITIVE AIRWAY PRESSURE ON MUSCLE SYMPATHETIC NERVE ACTIVITY IN PATIENTS WITH HEART FAILURE

Long-term adaptive servo-ventilation (ASV) increases cardiac function more effectively than continuous positive airway pressure (CPAP), possibly via alleviating sympathetic overactivation by respiratory stabilization. The present study evaluated the effect of ASV and CPAP at comparable pressure on