Percutaneous ventricular restoration using the parachute device in patients with ischemic heart failure: three-year outcomes of the PARACHUTE first-in-human study

BACKGROUND

Left ventricle remodeling after anterior wall myocardial infarction leads to increased left ventricle volumes, myocardial stress, and ultimately heart failure (HF). Treatment options are limited for these high-risk HF patients. A study was conducted to assess safety and feasibility of a percutaneous ventricular restoration therapy using the Parachute device in subjects with HF because of a cardiac ischemic event.

METHODS AND RESULTS

Thirty-nine subjects with New York Heart Association class II to IV ischemic HF, ejection fraction between 15% and 40%, and dilated akinetic or dyskinetic anterior-apical wall without the need to be revascularized were enrolled in a prospective, nonrandomized, multicenter investigation testing percutaneous ventricular restoration using the Parachute device. The safety primary end point was defined as successful procedure without device-related major adverse cardiac events during 6 months. Clinical and echocardiographic outcomes were obtained at 6, 12, 24, and 36 months post-treatment. Echocardiographic and end point data were adjudicated independently. Of the 39 subjects enrolled, device implantation was attempted in 34 and successful in 31 patients. Twenty-three subjects reached 3 years post-treatment with the device implanted. New York Heart Association symptom class was improved or maintained in 85% of subjects. Left ventricle end-diastolic volume index and end-systolic volume index were reduced from 128.4±22.1 and 94.9±22.3 mL/m(2) preimplant to 115.2±23.1 and 87.3±18.7 mL/m(2) at 3-year follow-up (end-diastolic volume index, P=0.0056; end-systolic volume index, P=0.4719). The cumulative incidence of HF hospitalization or death was 16.1%, 32.3%, and 38.7% at 12, 24, and 36 months, respectively. By 3-year follow-up, 2 (6.5%) of 31 patients with successful implant had died from cardiac reasons, with no cardiac deaths occurring past 6 months post-treatment.

CONCLUSIONS

The first series of ischemic HF patients treated with percutaneous ventricular restoration using the Parachute device demonstrates feasibility and safety of the device ≤3 years post-treatment.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifiers: NCT00573560 (US patients) and NCT01286116 (EU patients).

Current challenges for clinical trials of cardiovascular medical devices

Several features of cardiovascular devices raise considerations for clinical trial conduct. Prospective, randomized, controlled trials remain the highest quality evidence for safety and effectiveness assessments, but, for instance, blinding may be challenging. In order to avoid bias and not confound data interpretation, the use of objective endpoints and blinding patients, study staff, core labs, and clinical endpoint committees to treatment assignment are helpful approaches. Anticipation of potential bias should be considered and planned for prospectively in a cardiovascular device trial. Prospective, single-arm studies (often referred to as registry studies) can provide additional data in some cases. They are subject to selection bias even when carefully designed; thus, they are generally not acceptable as the sole basis for pre-market approval of high risk cardiovascular devices. However, they complement the evidence base and fill the gaps unanswered by randomized trials. Registry studies present device safety and effectiveness in day-to-day clinical practice settings and detect rare adverse events in the post-market period. No single research design will be appropriate for every cardiovascular device or target patient population. The type of trial, appropriate control group, and optimal length of follow-up will depend on the specific device, its potential clinical benefits, the target patient population and the existence (or lack) of effective therapies, and its anticipated risks. Continued efforts on the part of investigators, the device industry, and government regulators are needed to reach the optimal approach for evaluating the safety and performance of innovative devices for the treatment of cardiovascular disease.

Abstract 215: Principal Components Analysis in a South Asian Population: Cardiovascular Risk Variable Clustering and Obesity

Aim: Western populations demonstrate a strong role of obesity in clustering of cardiovascular (CV) risk factors. We hypothesized that obesity would not have a dominant role in the clustering of CV risk factors in South Asians, who develop CV disease at young ages despite relatively low BMI.

Methods: We selected 6224 South Indians without diabetes from a population-based cross-sectional survey (mean age 42 years; 58% women) for analysis. We used gender-specific principal components analysis (PCA), a multivariate correlation technique, with orthogonal rotation (to produce interpretable factors) to test the hypothesis. The PCA was done using measures of fasting (FPG) and 2 h plasma glucose (2h PG), haemoglobin A1c (A1c), fasting insulin (FIns), triglycerides (TG) and high-density lipoprotein (HDL), diastolic (DBP) and systolic blood pressure (SBP), body mass index (BMI) and waist circumference (WC). We did separate subgroup analyses stratified by various potential modifiers.

Results: The obesity indices correlated positively with CV risk variables (except HDL), regardless of gender. PCA failed to demonstrate a single dominant underlying pathological role (one component was rejected at P < 0.0001), but suggested three non-overlapping factors (physiological domains) underlying the clustering of the risk variables, accounting for 60% of the total variance in the data [Fig]. Obesity indices had significant positive loading (95% confidence interval >0.8) only in Factor 1, which included FIns, TG, and HDL. The FPG, 2hPG and A1C were associated with Factor 2. The SBP and DBP were associated with Factor 3. The factor patterns were virtually identical among all the subgroups with coefficients of congruence close to 1.0.

Conclusions: These findings are consistent with the presence of three distinct physiological domains underlying CV risk variable clustering. Obesity did not have a dominant role in the clustering of CV risk factors in the South Asian population.

Disease management: remote monitoring in heart failure patients with implantable defibrillators, resynchronization devices, and haemodynamic monitors

Heart failure represents a major public health concern, associated with high rates of morbidity and mortality. A particular focus of contemporary heart failure management is reduction of hospital admission and readmission rates. While optimal medical therapy favourably impacts the natural history of the disease, devices such as cardiac resynchronization therapy devices and implantable cardioverter defibrillators have added incremental value in improving heart failure outcomes. These devices also enable remote patient monitoring via device-based diagnostics. Device-based measurement of physiological parameters, such as intrathoracic impedance and heart rate variability, provide a means to assess risk of worsening heart failure and the possibility of future hospitalization. Beyond this capability, implantable haemodynamic monitors have the potential to direct day-to-day management of heart failure patients to significantly reduce hospitalization rates. The use of a pulmonary artery pressure measurement system has been shown to significantly reduce the risk of heart failure hospitalization in a large randomized controlled study, the CardioMEMS Heart Sensor Allows Monitoring of Pressure to Improve Outcomes in NYHA Class III Heart Failure Patients (CHAMPION) trial. Observations from a pilot study also support the potential use of a left atrial pressure monitoring system and physician-directed patient self-management paradigm; these observations are under further investigation in the ongoing LAPTOP-HF trial. All these devices depend upon high-intensity remote monitoring for successful detection of parameter deviations and for directing and following therapy.

Implantable Defibrillators Improve Survival in Patients With Mildly Symptomatic Heart Failure Receiving Cardiac Resynchronization Therapy

Background—

Cardiac resynchronization therapy (CRT) decreases mortality, improves functional status, and induces reverse left ventricular remodeling in selected populations with heart failure. These benefits have been noted with both CRT-pacemakers as well as those devices with defibrillator backup (CRT-D). However, there are little data comparing mortality between these 2 device types.

Methods and Results—

REsynchronization reVErses Remodeling in Systolic left vEntricular dysfunction (REVERSE) was a multicenter, randomized trial of CRT among patients with mild heart failure. Long-term annual follow-up for 5 years was preplanned. The present analysis was confined to the 419 patients who were randomized to active CRT group. CRT-pacemakers or CRT-D devices were implanted based on national guidelines at the time of enrollment, with 74 patients receiving CRT pacemaker devices and the remaining 345 patients receiving CRT-D devices. After 12 months of CRT, changes in the clinical composite score, left ventricular end systolic volume index, 6-minute walk time, and quality of life indices were similar between CRT pacemaker and CRT-D patients. However, long-term follow-up showed lower morality in the CRT-D group. Specifically, multivariable analysis showed that CRT-D (hazard ratio, 0.35; P =0.003) was a strong independent predictor of survival. Female sex, longer unpaced QRS duration, and smaller baseline left ventricular end systolic volume index also were also associated with better survival.

Conclusions—

REVERSE demonstrated that the addition of implantable cardioverter-defibrillator therapy to CRT is associated with improved long-term survival compared with CRT pacing alone in mild heart failure.

Clinical Trial Registration—

URL: http://clinicaltrials.gov . Unique Identifier: NCT00271154.

An individual patient meta-analysis of five randomized trials assessing the effects of cardiac resynchronization therapy on morbidity and mortality in patients with symptomatic heart failure

AIMS

Cardiac resynchronization therapy (CRT) with or without a defibrillator reduces morbidity and mortality in selected patients with heart failure (HF) but response can be variable. We sought to identify pre-implantation variables that predict the response to CRT in a meta-analysis using individual patient-data.

METHODS AND RESULTS

An individual patient meta-analysis of five randomized trials, funded by Medtronic, comparing CRT either with no active device or with a defibrillator was conducted, including the following baseline variables: age, sex, New York Heart Association class, aetiology, QRS morphology, QRS duration, left ventricular ejection fraction (LVEF), and systolic blood pressure. Outcomes were all-cause mortality and first hospitalization for HF or death. Of 3782 patients in sinus rhythm, median (inter-quartile range) age was 66 (58-73) years, QRS duration was 160 (146-176) ms, LVEF was 24 (20-28)%, and 78% had left bundle branch block. A multivariable model suggested that only QRS duration predicted the magnitude of the effect of CRT on outcomes. Further analysis produced estimated hazard ratios for the effect of CRT on all-cause mortality and on the composite of first hospitalization for HF or death that suggested increasing benefit with increasing QRS duration, the 95% confidence bounds excluding 1.0 at ∼140 ms for each endpoint, suggesting a high probability of substantial benefit from CRT when QRS duration exceeds this value.

CONCLUSION

QRS duration is a powerful predictor of the effects of CRT on morbidity and mortality in patients with symptomatic HF and left ventricular systolic dysfunction who are in sinus rhythm. QRS morphology did not provide additional information about clinical response.

CLINICALTRIALSGOV NUMBERS

NCT00170300, NCT00271154, NCT00251251.

Integrated microscopy techniques for comprehensive pathology evaluation of an implantable left atrial pressure sensor

The safety and efficacy of an implantable left atrial pressure (LAP) monitoring system is being evaluated in a clinical trial setting. Because the number of available specimens from the clinical trial for histopathology analysis is limited, it is beneficial to maximize the usage of each available specimen by relying on integrated microscopy techniques. The aim of this study is to demonstrate how a comprehensive pathology analysis of a single specimen may be reliably achieved using integrated microscopy techniques. Integrated microscopy techniques consisting of high-resolution gross digital photography followed by micro-computed tomography (micro-CT) scanning, low-vacuum scanning electron microscopy (LVSEM), and microground histology with special stains were applied to the same specimen. Integrated microscopy techniques were applied to eight human specimens. Micro-CT evaluation was beneficial for pinpointing the location and position of the device within the tissue, and for identifying any areas of interest or structural flaws that required additional examination. Usage of LVSEM was reliable in analyzing surface topography and cell type without destroying the integrity of the specimen. Following LVSEM, the specimen remained suitable for embedding in plastic and sectioning for light microscopy, using the positional data gathered from the micro-CT to intersect areas of interest in the slide. Finally, hematoxylin and eosin (H&E) and methylene blue staining was deployed on the slides with high-resolution results. The integration of multiple techniques on a single specimen maximized the usage of the limited number of available specimens from the clinical trial setting. Additionally, this integrated microscopic evaluation approach was found to have the added benefit of providing greater assurance of the derived conclusions because it was possible to cross-validate the results from multiple tests on the same specimen.

Sleep-disordered breathing in heart failure: identifying and treating an important but often unrecognized comorbidity in heart failure patients

Sleep-disordered breathing (SDB) is the most common comorbidity in patients with heart failure (HF) and has a significant impact on quality of life, morbidity, and mortality. A number of therapeutic options have become available in recent years that can improve quality of life and potentially the outcomes of HF patients with SDB. Unfortunately, SDB is not part of the routine evaluation and management of HF, so it remains untreated in most HF patients. Although recognition of the role of SDB in HF is increasing, clinical guidelines for the management of SDB in HF patients continue to be absent. This article provides an overview of SDB in HF and proposes a clinical care pathway to help clinicians to better recognize and treat SDB in their HF patients.

Cardiac-resynchronization therapy in heart failure with a narrow QRS complex

BACKGROUND

Cardiac-resynchronization therapy (CRT) reduces morbidity and mortality in chronic systolic heart failure with a wide QRS complex. Mechanical dyssynchrony also occurs in patients with a narrow QRS complex, which suggests the potential usefulness of CRT in such patients.

METHODS

We conducted a randomized trial involving 115 centers to evaluate the effect of CRT in patients with New York Heart Association class III or IV heart failure, a left ventricular ejection fraction of 35% or less, a QRS duration of less than 130 msec, and echocardiographic evidence of left ventricular dyssynchrony. All patients underwent device implantation and were randomly assigned to have CRT capability turned on or off. The primary efficacy outcome was the composite of death from any cause or first hospitalization for worsening heart failure.

RESULTS

On March 13, 2013, the study was stopped for futility on the recommendation of the data and safety monitoring board. At study closure, the 809 patients who had undergone randomization had been followed for a mean of 19.4 months. The primary outcome occurred in 116 of 404 patients in the CRT group, as compared with 102 of 405 in the control group (28.7% vs. 25.2%; hazard ratio, 1.20; 95% confidence interval [CI], 0.92 to 1.57; P=0.15). There were 45 deaths in the CRT group and 26 in the control group (11.1% vs. 6.4%; hazard ratio, 1.81; 95% CI, 1.11 to 2.93; P=0.02).

CONCLUSIONS

In patients with systolic heart failure and a QRS duration of less than 130 msec, CRT does not reduce the rate of death or hospitalization for heart failure and may increase mortality. (Funded by Biotronik and GE Healthcare; EchoCRT ClinicalTrials.gov number, NCT00683696.).

Clinical response with adaptive CRT algorithm compared with CRT with echocardiography-optimized atrioventricular delay: a retrospective analysis of multicentre trials

AIMS

Adaptive cardiac resynchronization therapy (aCRT) is a novel algorithm for CRT pacing that provides automatic ambulatory selection between synchronized left ventricular (LV) or bi-ventricular (BiV) pacing and optimization of atrioventricular (AV) and inter-ventricular (VV) delays based on periodic measurement of intrinsic conduction. We aimed to compare the clinical response between aCRT and standard CRT in historical trials.

METHODS AND RESULTS

The treatment arm of the aCRT trial was compared with a pooled historical control (HC) derived from the CRT arms of four clinical trials (MIRACLE, MIRACLE ICD, PROSPECT, and InSync III Marquis) with respect to the proportion of patients who had an improved clinical composite score (CCS) at the 6-month follow-up. Patients in the HC underwent echocardiography-guided AV optimization after the implant. A propensity score model was used to adjust for 22 potential baseline confounders of the effect of CRT. Patients were stratified into quintiles according to the propensity score and the adjusted absolute treatment effect was obtained by averaging estimates across these quintiles. The propensity score model included 751 patients (aCRT: 266, historical trials: 485). The adjusted absolute difference in percent improved in CCS between the aCRT and HC arms was 11.9% [95% confidence interval (CI): 2.7-19.2%] favouring aCRT. The patients in the aCRT group were significantly more likely to have an improved CCS than the patients in the HC (odds ratio = 1.65, 95% CI: 1.1-2.5).

CONCLUSION

The aCRT algorithm may be associated with additional improvement in clinical response compared with historical CRT with echocardiographic AV optimization.

Abstract 412: Obesity is an Independent Predictor Of Arterial Stiffness

Background Arterial stiffness assessed by carotid-femoral pulse wave velocity (PWV) is an independent predictor of cardiovascular morbidity and mortality. We aimed to investigate how various measures of obesity affect arterial stiffness.

Methods We conducted a population-based cross-sectional survey in 8,042 South Indians above the age of 20 years. Following completion of a detailed medical history questionnaire, all participants underwent haemodynamic screening including brachial and central blood pressure, and PWV measurements using a high-fidelity applanation tonometry. The study included anthropometric measurements and fasting blood for total cholesterol (TC), triglyceride (TG), high density lipoprotein (HDL), low density lipoprotein (LDL) and blood glucose (BG) levels. After the exclusion of people with previous history of diabetes, hypertension and dyslipidemia on drug therapy, 5,841 subjects (mean age 41.6 years; 58% women) constituted the study sample

Results In an univariate analysis, PWV correlated positively with age, mean blood pressure (MAP), heart rate (HR), body mass index (BMI), waist circumference (WC), waist to hip ratio (WHR), body fat percent (BF%), TC, TG, LDL and BG levels (P <0.001) and negatively with HDL levels (P=0.005). In a multivariate regression analysis, majority of the PWV variability in the model was accounted for by MAP and age, (cumulative adjusted R2 change of 32.79% as compared to the total adjusted R2 change of 35.25%). However, BMI (β= 0.042; adjusted R2 change=2.83%; p<0.001) independently correlated with PWV and its contribution to the PWV variability was far more significant compared to LDL, BG and TG (cumulative adjusted R2 change=1.08%). Multivariate regression analysis using the WC, WHR, or BF% instead of the BMI continued to demonstrate a significant independent effect of obesity parameters on PWV.

Conclusion: In a large a population-based cross-sectional survey the study demonstrates a positive, independent association between obesity parameters and increased arterial stiffness.

Wearable cardioverter-defibrillator use in patients perceived to be at high risk early post-myocardial infarction

OBJECTIVES

The aim of this study was to describe usage of the wearable cardioverter-defibrillator (WCD) during mandated waiting periods following myocardial infarction (MI) for patients perceived to be at high risk for sudden cardiac arrest (SCA).

BACKGROUND

Current device guidelines and insurance coverage require waiting periods of either 40 days or 3 months before implanting a cardioverter-defibrillator post-myocardial infarction (MI), depending on whether or not acute revascularization was undertaken.

METHODS

We assessed characteristics of and outcomes for patients who had a WCD prescribed in the first 3 months post-MI. The WCD medical order registry was searched for patients who were coded as having had a "recent MI with ejection fraction ≤35%" or given an International Classification of Diseases, Ninth Revision 410.xx diagnostic code (acute MI), and then matched to device-recorded data.

RESULTS

Between September 2005 and July 2011, 8,453 unique patients (age 62.7 ± 12.7 years, 73% male) matched study criteria. A total of 133 patients (1.6%) received 309 appropriate shocks. Of these patients, 91% were resuscitated from a ventricular arrhythmia. For shocked patients, the left ventricular ejection fraction (LVEF) was ≤30% in 106, 30% to 35% in 17, >36% in 8, and not reported in 2 patients. Of the 38% of patients not revascularized, 84% had a LVEF ≤30%; of the 62% of patients revascularized, 77% had a LVEF ≤30%. The median time from the index MI to WCD therapy was 16 days. Of the treated patients, 75% received treatment in the first month, and 96% within the first 3 months of use. Shock success resulting in survival was 84% in nonrevascularized and 95% in revascularized patients.

CONCLUSIONS

During the 40-day and 3-month waiting periods in patients post-MI, the WCD successfully treated SCA in 1.4%, and the risk was highest in the first month of WCD use. The WCD may benefit individual patients selected for high risk of SCA early post-MI.

Long-term impact of cardiac resynchronization therapy in mild heart failure: 5-year results from the REsynchronization reVErses Remodeling in Systolic left vEntricular dysfunction (REVERSE) study

BACKGROUND

The benefit of cardiac resynchronization therapy (CRT) among patients with mild heart failure (HF), reduced left ventricular (LV) function and wide QRS is well established. We studied the long-term stability of CRT.

METHODS

REVERSE was a randomized, double-blind study on CRT in NYHA Class I and II HF patients with QRS ≥120 ms and left ventricular ejection fraction (LVEF) ≤40%. After the randomized phase, all were programmed to CRT ON and prospectively followed through 5 years for functional capacity, echocardiography, HF hospitalizations, mortality, and adverse events. We report the results of the 419 patients initially assigned to CRT ON.

FINDINGS

The mean follow-up time was 54.8 ± 13.0 months. After 2 years, the functional and LV remodelling improvements were maximal. The 6-min hall walk increased by 18.8 ± 102.3 m and the Minnesota and Kansas City scores improved by 8.2 ± 17.8 and 8.2 ± 17.2 units, respectively. The mean decrease in left ventricular end-systolic volume index and left ventricular end-diastolic volume index was 23.5 ± 34.1 mL/m(2) (P < 0.0001) and 25.4 ± 37.0 mL/m2 (P < 0.0001) and the mean increase in LVEF 6.0 ± 10.8% (P < 0.0001) with sustained improvement thereafter. The annualized and 5-year mortality was 2.9 and 13.5% and the annualized and 5-year rate of death or first HF hospitalization 6.4, and 28.1%. The 5-year LV lead-related complication rate was 12.5%.

CONCLUSION

In patients with mild HF, CRT produced reverse LV remodelling accompanied by very low mortality and need for heart failure hospitalization. These effects were sustained over 5 years. Cardiac resynchronization therapy in addition to optimal medical therapy produces long-standing clinical benefits in mild heart failure.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov identifier NCT00271154.

The PARACHUTE IV trial design and rationale: percutaneous ventricular restoration using the parachute device in patients with ischemic heart failure and dilated left ventricles

BACKGROUND

Left ventricle (LV) remodeling after anterior wall myocardial infarction leads to increased LV volumes, myocardial stress, and, ultimately, heart failure (HF). Patients have high morbidity and mortality risk, and treatment remains limited. Percutaneous ventricular restoration (PVR) therapy using the Parachute device, a fluoropolymer membrane stretched over a nitinol conical frame, is a novel approach to partition off the damaged myocardium. In the European and United States PARACHUTE feasibility trials, the observed rates of death or rehospitalization for HF were <17% at 12 months. These data compare favorably with historical data and support the need of a randomized trial to determine the clinical efficacy of PVR on outcomes for patients with ischemic HF.

OBJECTIVE

To determine the safety and efficacy of PVR utilizing a LV partitioning device, Parachute, in a randomized clinical trial compared with optimal medical therapy.

METHODS

This US pivotal trial is approved by the Food and Drug Administration (ClinicalTrials.gov Identifier: NCT01286116) and will randomly assign (1:1) 478 patients with New York Heart Association class III-IV ischemic HF, akinetic or dyskinetic LV wall abnormality, and ejection fraction between 15% and 35% to optimal medical therapy (control) versus Parachute device implantation in approximately 65 hospitals. The primary endpoint is death or rehospitalization for worsening HF. Sample size calculation assumes constant hazards and follow-up ≥12 months using an event-driven trial design.

CONCLUSIONS

We reported the rational and design of the first multicenter randomized trial to test the efficacy of PVR using the Parachute device to treat patients with ischemic HF and dilated LV.

Effects of exercise on left ventricular systolic and diastolic properties in patients with heart failure and a preserved ejection fraction versus heart failure and a reduced ejection fraction

BACKGROUND

The purpose of the current study was to define exercise-induced changes in indices of left ventricular (LV) systolic and diastolic properties in patients with chronic heart failure (HF), compare these changes in patients with HF and a reduced ejection fraction (EF) versus HF and a preserved EF, and compare the hemodynamic responses to activities of daily living with symptom-limited upright exercise.

METHODS AND RESULTS

Subjects with HF and a preserved EF (n=8) and subjects with HF and a reduced EF (n=5) underwent symptom-limited Naughton protocol treadmill exercise tests. Implantable hemodynamic monitor data and echocardiographic data were obtained before exercise and at peak exercise. Implantable hemodynamic monitor data were obtained during activities of daily living during a 24-hour time period. In patients with HF and a reduced EF, limited exercise time (639±164 seconds) was associated with a marked rise in right ventricular systolic, diastolic, and estimated pulmonary artery diastolic (ePAD) pressures and an increase in LV end diastolic volume (EDV). LV systolic properties, namely EF, end systolic elastance, stroke work, and preload recruitable stroke work, all decreased. The ePAD/EDV ratio increased; to a large extent, this was dependent on an increase in EDV. By contrast, in HF and a preserved EF, limited exercise time (411±128 seconds) and the marked rise in right ventricular systolic, diastolic, and ePAD pressures were associated with no change in LV EDV. LV systolic properties increased or were unchanged; ePAD/EDV ratio increased during exercise, but the increase was independent of a change in EDV. The ranges of right ventricular systolic, diastolic, and ePAD pressures during activities of daily living were higher than the ranges of these values during the exercise stress test.

CONCLUSIONS

Although exercise limitations were similar between HF and a reduced EF and HF and a preserved EF, there were significant differences in exercise-induced changes in LV systolic and diastolic properties. These differences likely reflect the different pathophysiologies of these clinical syndromes of HF.