Rowenna Byrom

Cardiac resynchronization therapy in pacemaker-dependent patients with left ventricular dysfunction

AIMS Heart failure and left ventricular (LV) systolic dysfunction (LVSD) are common in patients with permanent pacemakers. The aim was to determine if cardiac resynchronization therapy (CRT) at the time of pulse generator replacement (PGR) is of benefit in patients with unavoidable RV pacing and LVSD. METHODS AND RESULTS Fifty patients with unavoidable RV pacing, LVSD, and mild or no symptoms of heart failure, listed for PGR were randomized 1 : 1 to either standard RV-PGR (comparator) or CRT. The primary endpoint was the difference in change in LV ejection fraction (LVEF) between RV-PGR and CRT groups from baseline to 6 months. Secondary endpoints included peak oxygen consumption, quality of life, and N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels. At 6 months there was a difference in change in median (interquartile range) LVEF [9 (6-12) vs. -1.5 (-4.5 to -0.8)%; P < 0.0001] between the CRT and RV-PGR arms. There were also improvements in exercise capacity (P = 0.007), quality of life (P = 0.03), and NT-proBNP (P = 0.007) in those randomized to CRT. After 809 (729-880) days, 17 patients had died or been hospitalized (6 in CRT group and 11 in the comparator RV-PGR group) and two patients in the RV-PGR arm had required CRT for deteriorating heart failure. Patients with standard RV-PGR had more days in hospital during follow-up than those in the CRT group [4 (2-7) vs. 11 (6-16) days; P = 0.047]. CONCLUSION Performing CRT in pacemaker patients with unavoidable RV pacing and LVSD but without severe symptoms of heart failure, at the time of PGR, improves cardiac function, exercise capacity, quality of life, and NT-pro-BNP levels.

Socioeconomic deprivation and mode-specific outcomes in patients with chronic heart failure

Objective To characterise the association between socioeconomic deprivation and adverse outcomes in patients with chronic heart failure (CHF). Methods We prospectively observed 1802 patients with CHF and left ventricular ejection fraction (LVEF) ≤45%, recruited in four UK hospitals between 2006 and 2014. We assessed the association between deprivation defined by the UK Index of Multiple Deprivation (IMD) and: mode-specific mortality (mean follow-up 4 years); mode-specific hospitalisation; and the cumulative duration of hospitalisation (after 1 year). Results A 45-point difference in mean IMD score was noted between patients residing in the least and most deprived quintiles of geographical regions. Deprivation was associated with age, sex and comorbidity, but not CHF symptoms, LVEF or prescribed drug therapy. IMD score was associated with the risk of age-sex adjusted all-cause mortality (6% higher risk per 10-unit increase in IMD score; 95% CI 2% to 10%; P=0.004), and non-cardiovascular mortality (9% higher risk per 10-unit increase in IMD score; 95% CI 3% to 16%; P=0.003), but not cardiovascular mortality. All-cause, but not heart failure-specific, hospitalisation was also more common in the most deprived patients. Overall, patients spent a cumulative 3.3 days in hospital during 1 year of follow-up, with IMD score being associated with the age-sex adjusted cumulative duration of hospitalisations (4% increase in duration per 10-unit increase in IMD score; 95% CI 3% to 6%; P<0.0005). Conclusions Socioeconomic deprivation in people with CHF is linked to increased risk of death and hospitalisation due to an excess of non-cardiovascular events.

Patients with long-term permanent pacemakers have a high prevalence of left ventricular dysfunction.

Introduction Patients with right ventricular pacemakers are at increased risk of left ventricular systolic dysfunction (LVSD). We aimed to establish the prevalence, degree and associations of LVSD in patients with long-term right ventricular pacemakers listed for pulse generator replacement (PGR). Methods All patients listed for PGR at Leeds General Infirmary were invited to attend for an assessment during which we recorded medical history, symptomatic status, medical therapy, date and indication of first implantation, the percentage of right ventricular pacing (% RVP) and an echocardiogram. Results We collected data on 491 patients. A left ventricular ejection fraction less than 50% was observed in 40% of our cohort, however, this was much higher (59%) in those with more than 80% RVP than in those with less than 80% RVP (22%) (P < 0.0001). Multivariable analysis revealed % RVP, (but not complete heart block at baseline), serum creatinine and previous myocardial infarction to be independently related to the presence of LVSD. A model combining % RVP and previous myocardial infarction has a c-statistic of 0.74 for predicting LVSD. After a mean follow-up time of 668 days, 56 patients (12%) were dead or had been hospitalized for heart failure. In multivariable analysis, previous myocardial infarction and high % RVP were independently associated with a worse survival. Conclusion Patients with right ventricular pacemakers have a high prevalence of LVSD, and this is greater in those exposed to more RVP. Those with LVSD and high amounts of RVP are at higher risk of hospitalization or death. Simple variables can identify those patients who might benefit from a more comprehensive review.

Clinical ResearchEditorial CommentMicronutrients for Chronic Heart Failure: End of the Road or Path to Enlightenment?∗

Patients and many physicians strongly believe in the positive effects of combined multiple micronutrient supplementation for the prevention and treatment of cardiovascular disease. This belief extends to patients with chronic heart failure (CHF), more than 60% of whom take some form of over-the-

Performance of 2014 NICE defibrillator implantation guidelines in heart failure risk stratification

Objective Define the real-world performance of recently updated National Institute for Health and Care Excellence guidelines (TA314) on implantable cardioverter-defibrillator (ICD) use in people with chronic heart failure. Methods Multicentre prospective cohort study of 1026 patients with stable chronic heart failure, associated with left ventricular ejection fraction (LVEF) ≤45% recruited in cardiology outpatient departments of four UK hospitals. We assessed the capacity of TA314 to identify patients at increased risk of sudden cardiac death (SCD) or appropriate ICD shock. Results The overall risk of SCD or appropriate ICD shock was 2.1 events per 100 patient-years (95% CI 1.7 to 2.6). Patients meeting TA314 ICD criteria (31.1%) were 2.5-fold (95% CI 1.6 to 3.9) more likely to suffer SCD or appropriate ICD shock; they were also 1.5-fold (95% CI 1.1 to 2.2) more likely to die from non-cardiovascular causes and 1.6-fold (95% CI 1.1 to 2.3) more likely to die from progressive heart failure. Patients with diabetes not meeting TA314 criteria experienced comparable absolute risk of SCD or appropriate ICD shock to patients without diabetes who met TA314 criteria. Patients with ischaemic cardiomyopathy not meeting TA314 criteria experienced comparable absolute risk of SCD or appropriate ICD shock to patients with non-ischaemic cardiomyopathy who met TA314 criteria. Conclusions TA314 can identify patients with reduced LVEF who are at increased relative risk of sudden death. Clinicians should also consider clinical context and the absolute risk of SCD when advising patients about the potential risks and benefits of ICD therapy.

Pacing-associated left ventricular dysfunction? Think reprogramming first!

Objective Heart failure and left ventricular systolic dysfunction (LVSD) are common in patients with permanent pacemakers, but whether right ventricular (RV) pacing is contributory or merely a bystander in patients with more severe cardiac disease is controversial. The aim of the present study was to determine whether reprogramming of existing pacemakers to reduce RV pacing is safe and leads to improvements in cardiac function. Methods This was a prospective service evaluation of the effects of optimising pacemaker programming to avoid RV pacing in 66 consecutive attendees of a teaching hospital pacemaker clinic without complete heart block. The main outcome measures were left ventricular ejection fraction (LVEF), N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) levels, quality of life and cardiopulmonary exercise testing at baseline and after 6 months. Results At 6 months, the protocol reduced absolute RV pacing by a mean of 49% (95% CI 41% to 57%) (p<0.0001 from baseline) and resulted in a mean absolute improvement in LVEF of 6% (4% to 8%) (p<0.0001 from baseline) but no reduction in exercise capacity, NT-pro-BNP or quality of life. There was a relationship between the magnitude of change in EF and the reduction in RV pacing (p=0.04) and changes in NT-pro-BNP seemed to relate to change in RV pacing (p=0.07). Conclusions Programming standard pacemakers to avoid RV pacing is safe, does not adversely affect patients’ symptoms or quality of life and is associated with improved LV function, related to the reductions in RV pacing percentage.

47 Using Natriuretic Peptide Levels to Diagnose Heart Failure in Primary Care: An Evaluation of the 2010 United Kingdom National Institute of Clinical Excellence Guidelines on the Diagnosis of Chronic Heart Failure

Introduction Chronic heart failure (HF) due to left ventricular systolic dysfunction (LVSD) is common and associated with high morbidity and mortality. The 2010 UK National Institute for Health and Care Excellence (NICE) guideline (CG-108) advises the measurement of natriuretic peptides (NP) in patients presenting to primary care with symptoms possibly due to HF without previous myocardial infarction (MI); with elevated concentrations triggering referral to a HF clinic. The aim of this study was to describe the results of implementation of the 2010 NP-based diagnostic guidelines for HF. Methods We prospectively collected demographic data from all patients in Leeds who underwent an NP test between 1st May 2012 and 1st May 2013. In those referred to the Leeds Integrated HF Service we collected clinical variables, electrocardiography and echocardiography data. Results Of the 4415 NT-pro-B-type NP tests performed in the twelve months to May 1st 2013, 543 (12%) returned a ‘high’ result (>2000 ng/L), and 1067 (24%) an ‘intermediate’ result (400–2000 ng/L). Of 1610 patients with an elevated result and no previous MI, 820 (51%) were referred to secondary care. Patients with a previous MI or a ‘high’ result were more likely to have LVSD (83/173, 48% and 131/245, 53% respectively), than those with ‘intermediate’ concentrations (112/447, 25%). Overall, the yield from 4263 NP tests (in patients without a previous MI) was 243 new diagnoses of LVSD. Conclusion Comprehensive implementation of the 2010 NICE guidelines for the diagnosis and management of HF has led to a large number of NT-pro-BNP tests and few new diagnoses.