Association of a device-based remote management heart failure pathway with outcomes: TriageHF Plus real-world evaluation.

AIMS: Clinical pathways have been shown to improve outcomes in patients with heart failure (HF). Although patients with HF often have a cardiac implantable electronic device, few studies have reported the utility of device-derived risk scores to augment and organize care. TriageHF Plus is a device-based HF clinical pathway (DHFP) that uses remote monitoring alerts to trigger structured telephone assessment for HF stability and optimization. We aimed to evaluate the impact of TriageHF Plus on hospitalizations and describe the associated workforce burden. METHODS AND RESULTS: TriageHF Plus was a multi-site, prospective study that compared outcomes for patients recruited between April 2019 and February 2021. All alert-triggered assessments were analysed to determine the appropriateness of the alert and the workload burden. A negative-binomial regression with inverse probability treatment weighting using a time-matched usual care cohort was applied to estimate the effect of TriageHF Plus on non-elective hospitalizations. A post hoc pre-COVID-19 sensitivity analysis was also performed. The TriageHF Plus cohort (n = 443) had a mean age of 68.8 ± 11.2 years, 77% male (usual care cohort: n = 315, mean age of 66.2 ± 14.5 years, 65% male). In the TriageHF Plus cohort, an acute medical issue was identified following an alert in 79/182 (43%) cases. Fifty assessments indicated acute HF, requiring clinical action in 44 cases. At 30 day follow-up, 39/66 (59%) of initially symptomatic patients reported improvement, and 20 (19%) initially asymptomatic patients had developed new symptoms. On average, each assessment took 10 min. The TriageHF Plus group had a 58% lower rate of hospitalizations across full follow-up [incidence relative ratio: 0.42, 95% confidence interval (CI): 0.23-0.76, P = 0.004]. Across the pre-COVID-19 window, hospitalizations were 31% lower (0.69, 95% CI: 0.46-1.04, P = 0.077). CONCLUSIONS: These data represent the largest real-world evaluation of a DHFP based on multi-parametric risk stratification. The TriageHF Plus clinical pathway was associated with an improvement in HF symptoms and reduced all-cause hospitalizations.

A Modular Communicative Leadless Pacing-Defibrillator System.

BACKGROUND: The subcutaneous implantable cardioverter-defibrillator (ICD) is associated with fewer lead-related complications than a transvenous ICD; however, the subcutaneous ICD cannot provide bradycardia and antitachycardia pacing. Whether a modular pacing-defibrillator system comprising a leadless pacemaker in wireless communication with a subcutaneous ICD to provide antitachycardia and bradycardia pacing is safe remains unknown. METHODS: We conducted a multinational, single-group study that enrolled patients at risk for sudden death from ventricular arrhythmias and followed them for 6 months after implantation of a modular pacemaker-defibrillator system. The safety end point was freedom from leadless pacemaker-related major complications, evaluated against a performance goal of 86%. The two primary performance end points were successful communication between the pacemaker and the ICD (performance goal, 88%) and a pacing threshold of up to 2.0 V at a 0.4-msec pulse width (performance goal, 80%). RESULTS: We enrolled 293 patients, 162 of whom were in the 6-month end-point cohort and 151 of whom completed the 6-month follow-up period. The mean age of the patients was 60 years, 16.7% were women, and the mean (±SD) left ventricular ejection fraction was 33.1±12.6%. The percentage of patients who were free from leadless pacemaker-related major complications was 97.5%, which exceeded the prespecified performance goal. Wireless-device communication was successful in 98.8% of communication tests, which exceeded the prespecified goal. Of 151 patients, 147 (97.4%) had pacing thresholds of 2.0 V or less, which exceeded the prespecified goal. The percentage of episodes of arrhythmia that were successfully terminated by antitachycardia pacing was 61.3%, and there were no episodes for which antitachycardia pacing was not delivered owing to communication failure. Of 162 patients, 8 died (4.9%); none of the deaths were deemed to be related to arrhythmias or the implantation procedure. CONCLUSIONS: The leadless pacemaker in wireless communication with a subcutaneous ICD exceeded performance goals for freedom from major complications related to the leadless pacemaker, for communication between the leadless pacemaker and subcutaneous ICD, and for the percentage of patients with a pacing threshold up to 2.0 V at a 0.4-msec pulse width at 6 months. (Funded by Boston Scientific; MODULAR ATP ClinicalTrials.gov NCT04798768.).

Treatment Adherence in a Randomized Controlled Trial of Pirfenidone in HFpEF: Determinants and Impact on Efficacy.

OBJECTIVES: Medication adherence in patients with heart failure with preserved ejection fraction is unclear. This study sought to evaluate treatment adherence in the Pirfenidone in Patients with Heart Failure and Preserved Left Ventricular Ejection Fraction (PIROUETTE) trial. METHODS AND RESULTS: Adherence was evaluated through pill counts and diary cards. Univariable and multivariable regression models were used to assess the relationship between adherence and baseline characteristics. Instrumental variable regression was used to estimate the causal effect of pirfenidone treatment duration on myocardial fibrosis. Complete adherence data were available in 54 of 80 participants completing the trial. Mean adherence to study medication was 94.7% and 96.9% in the pirfenidone and placebo groups, respectively. Each additional day of treatment with pirfenidone resulted in a significant decrease in myocardial extracellular volume (-0.004%; 95% confidence interval: -0.007% to -0.001%; P = 0.007). Associations with adherence included older age, higher symptom burden, lower body weight, and smaller right ventricular size. CONCLUSION: Adherence to study medication in the PIROUETTE trial was very high among patients for whom complete adherence data were available. Importantly, each additional day of treatment reduced myocardial fibrosis. Potential predictors of adherence were identified. Implementation of improved methods for assessing adherence is required.

Impact of Myocardial Fibrosis on Cardiovascular Structure, Function and Functional Status in Heart Failure with Preserved Ejection Fraction.

Myocardial fibrosis, measured using cardiovascular magnetic resonance extracellular volume (ECV), is associated with adverse outcome in heart failure with preserved ejection fraction, but the mechanisms by which myocardial fibrosis exerts this deleterious effect are unclear. We performed mediation analyses of data from the Pirfenidone in Patients with Heart Failure and Preserved Left Ventricular Ejection Fraction (PIROUETTE) trial to determine whether myocardial fibrotic regression causes changes in cardiovascular function and functional status following antifibrotic therapy. Regression of myocardial fibrosis correlated with improvements in 6-min walk test and KCCQ clinical summary score. The only outcome variable that demonstrated a treatment effect was an increase in left ventricular ejection fraction (LVEF). The estimated average causal mediation effects of myocardial ECV, absolute myocardial extracellular matrix volume and absolute myocardial cellular volume on LVEF were 6.1%, 21.5% and 13.7%, respectively, none of which was significant and therefore not mediated by myocardial fibrosis. (PIROUETTE; NCT02932566).

Characteristics Associated With Growth Differentiation Factor 15 in Heart Failure With Preserved Ejection Fraction and the Impact of Pirfenidone.

Background Growth differentiation factor 15 (GDF-15) is elevated in heart failure with preserved ejection fraction and is associated with adverse outcome, but its relationship with myocardial fibrosis and other characteristics remains unclear. We sought to evaluate the effect of pirfenidone, a novel antifibrotic agent, on GDF-15 in heart failure with preserved ejection fraction and identify characteristics that associate with GDF-15 and with change in GDF-15 over 1 year. Methods and Results Among patients enrolled (n=107) in the PIROUETTE (Pirfenidone in Patients With Heart Failure and Preserved Left Ventricular Ejection Fraction) trial, GDF-15 was measured at baseline and at prespecified time points in patients randomized (n=94) to pirfenidone or placebo. The response of GDF-15 to pirfenidone and the association with baseline patient characteristics were evaluated. Pirfenidone had no impact on circulating GDF-15 at any time point during the 52-week trial period. In multivariable analysis, male sex, diabetes, higher circulating levels of N-terminal pro-B-type natriuretic peptide, lower renal function, and shorter 6-minute walk test distance at baseline were associated with baseline log-GDF-15. Impaired global longitudinal strain at baseline was the strongest predictor of increased GDF-15 over 52 weeks. Conclusions In patients with heart failure with preserved ejection fraction, circulating levels of GDF-15 were unaffected by treatment with pirfenidone and do not appear to be determined by myocardial fibrosis. Circulating GDF-15 was associated with a spectrum of important heart failure characteristics and it may represent a marker of overall physiological disruption. Registration URL: https://clinicaltrials.gov/ct2/show/NCT02932566; Unique identifier: NCT02932566.

Predictors of myocardial fibrosis and response to anti-fibrotic therapy in heart failure with preserved ejection fraction.

Myocardial fibrosis, measured using magnetic resonance extracellular volume (ECV), associates with adverse outcome in heart failure with preserved ejection fraction (HFpEF). In the PIROUETTE (The Pirfenidone in Patients with Heart Failure and Preserved Left Ventricular Ejection Fraction) trial, the novel anti-fibrotic agent pirfenidone reduced myocardial fibrosis. We sought to identify baseline characteristics that associate with myocardial fibrotic burden, the change in myocardial fibrosis over a year, and predict response to pirfenidone in patients with HFpEF. Amongst patients enrolled in the PIROUETTE trial (n = 107), linear regression models were used to assess the relationship between baseline variables and baseline myocardial ECV, with change in myocardial ECV adjusting for treatment allocation, and to identify variables that modified the pirfenidone treatment effect. Body mass index, left atrial reservoir strain, haemoglobin and aortic distensibility were associated with baseline ECV in stepwise modelling, and systolic blood pressure, and log N-terminal pro B-type natriuretic peptide were associated with baseline ECV in clinically-guided modelling. QRS duration, left ventricular mass and presence of an infarct at baseline were associated with an increase in ECV from baseline to week 52. Whilst QRS duration, presence of an infarct, global longitudinal strain and left atrial strain modified the treatment effect of pirfenidone when considered individually, no variable modified treatment effect on multivariable modelling. Baseline characteristics were identified that associate with myocardial fibrosis and predict change in myocardial fibrosis. No variables that independently modify the treatment effect of pirfenidone were identified (PIROUETTE, NCT02932566).

Ambulatory intravenous furosemide for decompensated heart failure: safe, feasible, and effective.

AIMS: This study aims to establish the feasibility, safety, and efficacy of outpatient intravenous (IV) diuretic treatment for the management of decompensated heart failure (HF) for patients enrolled in the HeartFailure@Home service. METHODS AND RESULTS: We retrospectively analysed the clinical episodes of decompensated HF for patients enrolled in the HeartFailure@Home service, managed by ambulatory IV diuretic treatment either at home or on a day-case unit. A control group consisting of HF patients admitted to hospital for IV diuretics (standard-of-care) was also evaluated. In total, 203 episodes of decompensated HF (n = 154 patients) were evaluated. One hundred and fourteen episodes in 79 patients were managed exclusively by the ambulatory IV diuretic service-78 (68.4%) on a day-case unit and 36 (31.6%) domiciliary; 84.1% of patient episodes under the HF@Home service were successfully managed entirely in an out-patient setting without hospitalization. Eleven patients required admission in order to administer higher doses of IV diuretics than could be provided in the ambulatory setting. During follow-up, there were 20 (17.5%) 30 day re-admissions with HF or death in the ambulatory IV group and 29 (32.6%) in the standard-of-care arm (P = 0.02). There was no difference in 30 day HF readmissions between the two groups (14.9% ambulatory vs. 13.5% inpatients, P = 0.8), but 30 day mortality was significantly lower in the ambulatory group (3.5% vs. 21.3% inpatients, P < 0.001). CONCLUSIONS: Outpatient ambulatory management of decompensated HF with IV diuretics given either on a day case unit or in a domiciliary setting is feasible, safe, and effective in selected patients with decompensated HF. This should be explored further as a model in delivering HF services in the outpatient setting during COVID-19.

Pirfenidone in heart failure with preserved ejection fraction: a randomized phase 2 trial.

In heart failure with preserved ejection fraction (HFpEF), the occurrence of myocardial fibrosis is associated with adverse outcome. Whether pirfenidone, an oral antifibrotic agent without hemodynamic effect, is efficacious and safe for the treatment of HFpEF is unknown. In this double-blind, phase 2 trial ( NCT02932566 ), we enrolled patients with heart failure, an ejection fraction of 45% or higher and elevated levels of natriuretic peptides. Eligible patients underwent cardiovascular magnetic resonance and those with evidence of myocardial fibrosis, defined as a myocardial extracellular volume of 27% or greater, were randomly assigned to receive pirfenidone or placebo for 52 weeks. Forty-seven patients were randomized to each of the pirfenidone and placebo groups. The primary outcome was change in myocardial extracellular volume, from baseline to 52 weeks. In comparison to placebo, pirfenidone reduced myocardial extracellular volume (between-group difference, -1.21%; 95% confidence interval, -2.12 to -0.31; P = 0.009), meeting the predefined primary outcome. Twelve patients (26%) in the pirfenidone group and 14 patients (30%) in the placebo group experienced one or more serious adverse events. The most common adverse events in the pirfenidone group were nausea, insomnia and rash. In conclusion, among patients with HFpEF and myocardial fibrosis, administration of pirfenidone for 52 weeks reduced myocardial fibrosis. The favorable effects of pirfenidone in patients with HFpEF will need to be confirmed in future trials.

Novel atrioventricular sequential pacing approach using a transvenous atrial pacemaker and a leadless pacemaker: a case report.

BACKGROUND: The use of transvenous pacing leads is associated with the risk of developing tricuspid valve (TV) dysfunction. This develops through several mechanisms including the failure of leaflet coaptation or direct damage to the TV or to its sub-valvular apparatus and can result in significant tricuspid regurgitation (TR). Multiple approaches to pacemaker implantation after transvenous lead extraction (TLE) or surgical TV repair have been described. Placement of pacing leads across the TV is generally avoided in such circumstances. CASE SUMMARY: A 66-year-old woman presented with a year-long history of exertional dyspnoea, peripheral oedema, and postural neck pulsations. Her medical history included a dual-chamber pacemaker implantation for sinus node dysfunction 14 years ago. Echocardiography revealed severe lead-related TR. Her case was discussed in our multi-disciplinary team meeting. A decision was made to perform a TLE and implant a leadless pacemaker in an attempt to avoid open-heart surgery if possible. This was reserved as an option in the event of persistent severe TR. Transvenous extraction of the right ventricular lead was performed. The atrial lead was preserved and connected to and AAI device. A Micra AV was implanted allowing for atrioventricular (AV) synchronous pacing. DISCUSSION: We present the first case of successful implementation of AV sequential pacing using a dual-pacemaker approach involving the use of an AAI pacemaker and a Micra AV device. This was performed after TLE for severe lead-related TR.

The impact of COVID-19 on the management of heart failure: a United Kingdom patient questionnaire study.

AIMS: The coronavirus disease 2019 (COVID-19) pandemic has created significant challenges to healthcare globally, necessitating rapid restructuring of service provision. This questionnaire survey was conducted amongst adult heart failure (HF) patients in the United Kingdom (UK), to understand the impact of COVID-19 upon HF services. METHODS AND RESULTS: The survey was conducted by the Pumping Marvellous Foundation, a UK HF patient charity. 'Survey Monkey' was used to disseminate the questionnaire in the Pumping Marvellous Foundation 's online patient group and in 10 UK hospitals (outpatient hospital and community HF clinics). There were 1050 responses collected (693/1050-66% women); 55% (579/1050) were aged over 60 years. Anxiety level was significantly higher regarding COVID-19 (mean 7 ± 2.5 on anxiety scale of 0 to 10) compared with anxiety regarding HF (6.1 ± 2.4; P < 0.001). Anxiety was higher amongst patients aged ≤60 years about HF (6.3 ± 2.2 vs. 5.9 ± 2.5 in those aged >60 years; P = 0.005) and COVID-19 (7.3 ± 2.3 vs. 6.7 ± 2.6 those aged >60 years; P < 0.001). Sixty-five per cent of respondents (686/1050) reported disruption to HF appointments (cancellation or postponement) during the lockdown period. Thirty-seven per cent reported disruption to medication prescription services, and Thirty-four per cent reported inability to access their HF teams promptly. Thirty-two per cent expressed reluctance to attend hospital (25% stated they would only attend hospital if there was no alternative, and 7% stated that they would not attend hospital at all). CONCLUSIONS: The COVID-19 pandemic has caused significant anxiety amongst HF patients regarding COVID-19 and HF. Cancellation or postponement of scheduled clinic appointments, investigations, procedures, prescription, and monitoring services were implicated as sources of anxiety.

An Unusual Cause of Pacemaker Lead Displacement: 'Reverse Ratchet' Syndrome.

Lead displacement is a common complication of pacemaker device implantation, often resulting in prolonged hospital stays and increased costs. The frequency of long-term lead displacement ranges between 1.8% and 8.0%. In our case, the patient did not present any symptoms and the lead displacement was seen at a relatively late stage. During a routine pacemaker follow up, it was noted that the right ventricular (RV) threshold had increased and deteriorated over time. The pacemaker box had rotated anticlockwise and the RV lead had developed a loop that eventually led to its retraction from the RV implantation position into the pulmonary artery. The patient was asymptomatic; however, he underwent RV lead revision. Patient education, opening an appropriate pocket for the size of the generator, fixing the sleeves to an appropriate tightness and securing the battery with a strong suture all can be used to avoid lead displacement.

Triage-HF Plus: a novel device-based remote monitoring pathway to identify worsening heart failure.

AIMS: Remote monitoring of patients with physiological data derived from cardiac implanted electronic devices (CIEDs) offers potential to reconfigure clinical services. The 'Heart Failure Risk Score' (HFRS) uses input from integrated device physiological monitoring to risk-stratify patients as low-risk, medium-risk, or high-risk of a heart failure event in the next 30 days. This study aimed to evaluate a novel clinical pathway utilizing a combination of CIED risk-stratification and telephone triage to identify patients with worsening heart failure (WHF). METHODS AND RESULTS: A prospective, single-centre, real-world evaluation of the 'Triage-HF Plus' clinical pathway (HFRS in combination with telephone triage) over a 27 month period. One hundred and fifty-seven high-risk HFRS transmissions were referred for telephone triage assessment. Interventions were at the discretion of the clinical assessor acting in accordance with clinical guidelines. An additional 3month consecutive sample of low and medium HFRS transmissions (control group) were also contacted for telephone triage assessment (n = 98). Successful telephone contact was made in 127 (81%) of referred high-risk HFRS cases: 71 (55.9%) were confirmed to have WHF requiring intervention; 19 (14.9%) had an alternative acute medical problem; one patient had been recently discharged from hospital with WHF; and 36 (28.0%) had no apparent cause for the high score. In the control group, only one patient had symptoms of WHF. The sensitivity and specificity of CIED-based remote monitoring to identify WHF 98.6% (92.5-100.0%) and 63.4% (55.2-71.0%), respectively. CONCLUSIONS: The Triage-HF Plus clinical pathway is a potentially useful remote monitoring tool for patients with heart failure and in situ CIEDs.

Pirfenidone in Heart Failure with Preserved Ejection Fraction-Rationale and Design of the PIROUETTE Trial.

BACKGROUND: The PIROUETTE (PIRfenidOne in patients with heart failUre and preserved lEfT venTricular Ejection fraction) trial is designed to evaluate the efficacy and safety of the anti-fibrotic pirfenidone in patients with chronic heart failure and preserved ejection fraction (HFpEF) and myocardial fibrosis. HFpEF is a diverse syndrome associated with substantial morbidity and mortality. Myocardial fibrosis is a key pathophysiological mechanism of HFpEF and myocardial fibrotic burden is strongly and independently associated with adverse outcome. Pirfenidone is an oral anti-fibrotic agent, without haemodynamic effect, that leads to regression of myocardial fibrosis in preclinical models. It has proven clinical effectiveness in pulmonary fibrosis. METHODS: The PIROUETTE trial is a randomised, double-blind, placebo-controlled phase II trial evaluating the efficacy and safety of 52 weeks of treatment with pirfenidone in patients with chronic HFpEF (symptoms and signs of heart failure, left ventricular ejection fraction ≥ 45%, elevated natriuretic peptides [BNP ≥ 100 pg/ml or NT-proBNP ≥ 300 pg/ml; or BNP ≥ 300 pg/ml or NT-proBNP ≥ 900 pg/ml if in atrial fibrillation]) and myocardial fibrosis (extracellular matrix (ECM) volume ≥ 27% measured using cardiovascular magnetic resonance). The primary outcome measure is change in myocardial ECM volume. A sub-study will investigate the relationship between myocardial fibrosis and myocardial energetics, and the impact of pirfenidone, using 31phosphorus magnetic resonance spectroscopy. DISCUSSION: PIROUETTE will determine whether pirfenidone is superior to placebo in relation to regression of myocardial fibrosis and improvement in myocardial energetics in patients with HFpEF and myocardial fibrosis (NCT02932566). CLINICAL TRIAL REGISTRATION: clinicaltrials.gov (NCT02932566) https://clinicaltrials.gov/ct2/show/NCT02932566.

Correction: Cardiac implantable electronic device (CIED) infections are expensive and associated with prolonged hospitalisation: UK Retrospective Observational Study.

[This corrects the article DOI: 10.1371/journal.pone.0206611.].

Cardiac implantable electronic device (CIED) infections are expensive and associated with prolonged hospitalisation: UK Retrospective Observational Study.

BACKGROUND: There are limited reports outlining the financial cost of treating cardiac implantable electronic device (CIED) infection outside the United States. This study aimed to determine the average treatment cost of CIED infection in a large UK tertiary referral centre and compared costs of different treatment pathways that are recognised in the management of CIED infection (early versus delayed re-implantation). METHODS: We retrospectively analysed cost and length of stay (LOS) data for consecutive patients undergoing infected CIED extraction with cardiac resynchronization therapy (CRT-D [with defibrillator], CRT-P [with pacemaker]), implantable cardioverter-defibrillators (ICDs) and permanent pacemakers (PPMs). RESULTS: Between January 2013 and March 2015, complete data was available for 84 patients (18 [21.4%] CRT-D, 24 [28.6%] ICDs and 42 [50.0%] PPMs). When all cases were considered the cost of infection ranged from £5,139 (PPM) to £24,318 (CRT-D). Considering different treatment strategies; 41 (48.8%) underwent CIED extraction and re-implantation during the same admission (early re-implant strategy (ER). 43 (51.2%) underwent extraction, but were then discharged home to be re-admitted for day-case re-implantation (delayed re-implant strategy (DR)). Median LOS was significantly shorter in DR compared to ER (5.0 vs. 18.0 days, p<0.001). The total cost of CIED infection episode was similar for both treatment strategies (median £14,241.48 vs. £14,741.70 including wearable defibrillator (Lifevest) and outpatient antibiotics costs, ER vs. DR; p = 0.491). CONCLUSION: CIED infections are expensive and associated with significant health-economic burden. When all device types were considered, a DR strategy is associated with reduced LOS without an increased cost penalty.

Cardiopulmonary exercise testing in the evaluation of liver disease in adults who have had the Fontan operation.

BACKGROUND: Liver disease (LD) is a long-term complication in patients with a single ventricle who have had the Fontan operation. A decline in cardiopulmonary exercise testing (CPET) variables is associated with increased risk of hospitalization, but its association with LD is unknown. AIM: To determine the association between CPET variables and LD in adults who have had the Fontan operation. METHODS: We retrospectively reviewed the medical records from two tertiary institutions. RESULTS: We identified 114 adults (≥18 years; mean 30.9±7.4 years) who had undergone the Fontan operation: 56% were women; 63% had total cavopulmonary connection; 66% had New York Heart Association (NYHA) class I status; 42% had arrhythmias; 22% had systemic right ventricle; and 35% had ventricular dysfunction. Of 81 patients with liver-imaging data, 41% had LD (i.e. imaging evidence of cirrhosis, with or without portal hypertension, splenomegaly or varices). There were no differences in clinical or echocardiographic variables between those with and without LD. Among the 58 patients with CPET data, mean peak oxygen consumption (VO2) was 18.6±5.7mL/kg/min, per-cent-predicted peak VO2 was 53.9±15.5%, peak oxygen pulse was 9.3±2.9mL/beat and per-cent-predicted peak oxygen pulse was 82.6±21.5%. Of the 44 patients with liver and CPET data, each standard deviation decrease in per-cent-predicted peak VO2 (16%) and per-cent-predicted peak oxygen pulse (22%) was associated with a 2.3-fold increase in the odds of LD, after adjusting for NYHA, institution and Fontan type (P=0.04). Similarly, each standard deviation decrease in per-cent-predicted peak VO2 and oxygen pulse was associated with an estimated 5.9-year and 4.9-year earlier onset of LD, respectively (P>0.05). CONCLUSIONS: Decline in per-cent-predicted peak VO2 and oxygen pulse was associated with increased odds of LD in adults who had undergone the Fontan operation. Our study supports more rapid hepatic evaluation among patients with abnormal or worsening CPET variables.

Biological Phenotypes of Heart Failure With Preserved Ejection Fraction.

Heart failure with preserved ejection fraction (HFpEF) involves multiple pathophysiological mechanisms, which result in the heterogeneous phenotypes that are evident clinically, and which have potentially confounded previous HFpEF trials. A greater understanding of the in vivo human processes involved, and in particular, which are the causes and which are the downstream effects, may allow the syndrome of HFpEF to be distilled into distinct diagnoses based on the underlying biology. From this, specific interventions can follow, targeting individuals identified on the basis of their biological phenotype. This review describes the biological phenotypes of HFpEF and therapeutic interventions aimed at targeting these phenotypes.

Totally Leadless Dual-Device Implantation for Combined Spontaneous Ventricular Tachycardia Defibrillation and Pacemaker Function: A First Report.

Subcutaneous implantable cardioverter defibrillators (S-ICDs) provide effective defibrillation, while also reducing the risk of long-term lead problems. However, S-ICDs do not offer bradycardia or antitachycardia pacing and therefore use has been limited. Combined implantation of an S-ICD with a leadless pacemaker (LP) has been proposed to overcome this limitation. Although a handful of combined S-ICD/LP implantations have been reported for Nanostim (St Jude Medical, St Paul, MN) as well as Micra LP (Medtronic, Minneapolis, MN) systems, none have documented delivery of appropriate shock therapies for spontaneous ventricular tachycardia. We report the first case of effective defibrillation for spontaneous ventricular tachycardia in a patient with combined Micra LP and S-ICD.

Efficacy and safety of the subcutaneous implantable cardioverter defibrillator: a systematic review.

BACKGROUND: Subcutaneous implantable cardioverter defibrillators (S-ICDs) are considered an alternative to conventional transvenous ICDs (TV-ICDs) in patients not requiring pacing. METHODS: We searched MEDLINE and EMBASE for studies evaluating efficacy and safety outcomes in S-ICD patients. Outcomes were pooled across studies. RESULTS: Sixteen studies were included with 5380 participants (mean age range 33-56 years). Short-term follow-up data were available for 1670 subjects. The most common complication was pocket infection, affecting 2.7%. Other complications included delayed wound healing (0.6%) and wound discomfort (0.8%). 3.8% of S-ICDs were explanted, most commonly for pocket infection. Mortality rates in hospital (0.4%) and during follow-up (3.4% from 12 studies reporting) were low. Incidence of ventricular arrhythmia varied from 0% to 12%. Overall shock efficacy exceeded 96%. Inappropriate shocks affected 4.3% and was most commonly caused by T-wave oversensing. CONCLUSIONS: Although long-term randomised data are lacking, observational data suggest similar shock efficacy and short-term complication rates between the S-ICD and TV-ICD.