Personalized Rate-Response Programming Improves Exercise Tolerance After 6 Months in People With Cardiac Implantable Electronic Devices and Heart Failure: A Phase II Study.

BACKGROUND: Heart failure with reduced ejection fraction (HFrEF) is characterized by blunting of the positive relationship between heart rate and left ventricular (LV) contractility known as the force-frequency relationship (FFR). We have previously described that tailoring the rate-response programming of cardiac implantable electronic devices in patients with HFrEF on the basis of individual noninvasive FFR data acutely improves exercise capacity. We aimed to examine whether using FFR data to tailor heart rate response in patients with HFrEF with cardiac implantable electronic devices favorably influences exercise capacity and LV function 6 months later. METHODS: We conducted a single-center, double-blind, randomized, parallel-group trial in patients with stable symptomatic HFrEF taking optimal guideline-directed medical therapy and with a cardiac implantable electronic device (cardiac resynchronization therapy or implantable cardioverter-defibrillator). Participants were randomized on a 1:1 basis between tailored rate-response programming on the basis of individual FFR data and conventional age-guided rate-response programming. The primary outcome measure was change in walk time on a treadmill walk test. Secondary outcomes included changes in LV systolic function, peak oxygen consumption, and quality of life. RESULTS: We randomized 83 patients with a mean±SD age 74.6±8.7 years and LV ejection fraction 35.2±10.5. Mean change in exercise time at 6 months was 75.4 (95% CI, 23.4 to 127.5) seconds for FFR-guided rate-adaptive pacing and 3.1 (95% CI, -44.1 to 50.3) seconds for conventional settings (analysis of covariance; P=0.044 between groups) despite lower peak mean±SD heart rates (98.6±19.4 versus 112.0±20.3 beats per minute). FFR-guided heart rate settings had no adverse effect on LV structure or function, whereas conventional settings were associated with a reduction in LV ejection fraction. CONCLUSIONS: In this phase II study, FFR-guided rate-response programming determined using a reproducible, noninvasive method appears to improve exercise time and limit changes to LV function in people with HFrEF and cardiac implantable electronic devices. Work is ongoing to confirm our findings in a multicenter setting and on longer-term clinical outcomes. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02964650.

Optimising pacemaker therapy and medical therapy in pacemaker patients for heart failure: protocol for the OPT-PACE randomised controlled trial.

INTRODUCTION: Permanent artificial pacemaker implantation is a safe and effective treatment for bradycardia and is associated with extended longevity and improved quality of life. However, the most common long-term complication of standard pacemaker therapy is pacemaker-associated heart failure. Pacemaker follow-up is potentially an opportunity to screen for heart failure to assess and optimise patient devices and medical therapy. METHODS AND ANALYSIS: The study is a multicentre, phase-3 randomised trial. The 1200 participants will be people who have a permanent pacemaker for bradycardia for at least 12 months, randomly assigned to undergo a transthoracic echocardiogram with their pacemaker check, thereby tailoring their management directed by left ventricular function or the pacemaker check alone, continuing with routine follow-up. The primary outcome measure is time to all-cause mortality or heart failure hospitalisation. Secondary outcomes include external validation of our risk stratification model to predict onset of heart failure and quality of life assessment. ETHICS AND DISSEMINATION: The trial design and protocol have received national ethical approval (12/YH/0487). The results of this randomised trial will be published in international peer-reviewed journals, communicated to healthcare professionals and patient involvement groups and highlighted using social media campaigns. TRIAL REGISTRATION NUMBER: NCT01819662.

Prospective evaluation and long-term follow-up of patients referred to secondary care based upon natriuretic peptide levels in primary care.

AIMS: The UK National Institute for Health and Care Excellence (UK-NICE) and European Society of Cardiology (ESC) guidelines advise natriuretic peptide (NP) assessment in patients presenting to primary care with symptoms possibly due to chronic heart failure (HF), to determine need for specialist involvement. This prospective service evaluation aimed to describe the diagnostic and prognostic utility of these guidelines. METHODS AND RESULTS: We prospectively collected clinical, echocardiography and outcomes data (minimum 5 years) from all patients referred to the Leeds HF Service for 12 months of following the initiation of the NP-guideline-directed pathway. Between 1 May 2012 and 1 August 2013, 1020 people with symptoms possibly due to HF attended either with a raised NT-pro-BNP or a previous myocardial infarction (MI) with an overall rate of left ventricular systolic dysfunction (LVSD) of 33%. Of these, 991 satisfied the ESC criteria (NT-pro-BNP ≥125 pg/mL) in whom the rate of LVSD was 32%, and 821 the UK-NICE criteria in whom the rate of LVSD was 49% in those with a previous MI, 25% in those with NT-pro-BNP concentration 400-2000 pg/mL, and 54% in those with NT-pro-BNP concentration of >2000 pg/mL. An NT-pro-BNP concentration 125-400 pg/mL had a 12% risk of LVSD. Specificity was poor in women >70 years, who made up the largest proportion of attendees. Elevated NT-pro-BNP levels were associated with lower survival even in the absence of LVSD. CONCLUSION: In people referred through the ESC and UK-NICE guidelines, elevated NT-pro-BNP is a marker of increased mortality risk, but there is wide variation in specificity for LVSD. Age- and sex-adjusted criteria might improve performance.

Effects of Vitamin D on Cardiac Function in Patients With Chronic HF: The VINDICATE Study.

BACKGROUND: Patients with chronic heart failure (HF) secondary to left ventricular systolic dysfunction (LVSD) are frequently deficient in vitamin D. Low vitamin D levels are associated with a worse prognosis. OBJECTIVES: The VINDICATE (VitamIN D treatIng patients with Chronic heArT failurE) study was undertaken to establish safety and efficacy of high-dose 25 (OH) vitamin D3 (cholecalciferol) supplementation in patients with chronic HF due to LVSD. METHODS: We enrolled 229 patients (179 men) with chronic HF due to LVSD and vitamin D deficiency (cholecalciferol <50 nmol/l [<20 ng/ml]). Participants were allocated to 1 year of vitamin D3 supplementation (4,000 IU [100 µg] daily) or matching non-calcium-based placebo. The primary endpoint was change in 6-minute walk distance between baseline and 12 months. Secondary endpoints included change in LV ejection fraction at 1 year, and safety measures of renal function and serum calcium concentration assessed every 3 months. RESULTS: One year of high-dose vitamin D3 supplementation did not improve 6-min walk distance at 1 year, but was associated with a significant improvement in cardiac function (LV ejection fraction +6.07% [95% confidence interval (CI): 3.20 to 8.95; p < 0.0001]); and a reversal of LV remodeling (LV end diastolic diameter -2.49 mm [95% CI: -4.09 to -0.90; p = 0.002] and LV end systolic diameter -2.09 mm [95% CI: -4.11 to -0.06 p = 0.043]). CONCLUSIONS: One year of 100 µg daily vitamin D3 supplementation does not improve 6-min walk distance but has beneficial effects on LV structure and function in patients on contemporary optimal medical therapy. Further studies are necessary to determine whether these translate to improvements in outcomes. (VitamIN D Treating patIents With Chronic heArT failurE [VINDICATE]; NCT01619891).