Rupinder Bharmi

Hospitalization rates and associated cost analysis of cardiac resynchronization therapy with an implantable defibrillator and quadripolar vs. bipolar left ventricular leads: a comparative effectiveness study.

Aims This study compares, from a prospective, observational, non-randomized registry, the post-implant hospitalization rates and associated healthcare resource utilization of cardiac resynchronization therapy-defibrillator (CRT-D) patients with quadripolar (QUAD) vs. bipolar (BIP) left ventricular (LV) leads. Methods and results Between January 2009 and December 2012, 193 consecutive patients receiving de novo CRT-D implants with either a QUAD (n = 116) or a BIP (n = 77) LV lead were enrolled at implant and followed until July 2013 at a single-centre, university hospital. Post-implant hospitalizations related to heart failure (HF) or LV lead surgical revision and associated payer costs were identified using ICD-9-CM diagnosis and procedure codes. Italian national reimbursement rates were determined. Propensity scores were estimated using a logistic regression model based upon 11 pre-implant baseline characteristics and were used to derive a 1 : 1 matched cohort of QUAD (n = 77) and BIP (n = 77) patients. Hospitalization rates for the two groups were compared using negative binomial regression and associated payer costs were compared using non-parametric bootstrapping (×10 000) and one-sided hypothesis test. Hospitalization rates of the QUAD group [0.15/ patient (pt)-year] were lower than those of the BIP group (0.32/ pt-year); the incidence rate ratio was 0.46, P = 0.04. The hospitalization costs for the QUAD group (434 ± 128 €/pt-year) were lower than those for the BIP group (1136 ± 362 €/pt-year). The average difference was 718 €/pt-year, P = 0.016. Conclusions In this comparative effectiveness assessment of well-matched groups of CRT-D patients with quadripolar and bipolar LV leads, QUAD patients experienced a lower rate of hospitalizations for HF and LV lead surgical revision, and a lower cost burden. This has important implications for LV pacing lead choice.

Spinal cord stimulation protects against atrial fibrillation induced by tachypacing

BACKGROUND Spinal cord stimulation (SCS) has been shown to modulate atrial electrophysiology and confer protection against ischemia and ventricular arrhythmias in animal models. OBJECTIVE To determine whether SCS reduces the susceptibility to atrial fibrillation (AF) induced by tachypacing (TP). METHODS In 21 canines, upper thoracic SCS systems and custom cardiac pacing systems were implanted. Right atrial and left atrial effective refractory periods were measured at baseline and after 15 minutes of SCS. Following recovery in a subset of canines, pacemakers were turned on to induce AF by alternately delivering TP and searching for AF. Canines were randomized to no SCS therapy (CTL) or intermittent SCS therapy on the initiation of TP (EARLY) or after 8 weeks of TP (LATE). AF burden (percent AF relative to total sense time) and AF inducibility (percentage of TP periods resulting in AF) were monitored weekly. After 15 weeks, echocardiography and histology were performed. RESULTS Effective refractory periods increased by 21 ± 14 ms (P = .001) in the left atrium and 29 ± 12 ms (P = .002) in the right atrium after acute SCS. AF burden was reduced for 11 weeks in EARLY compared with CTL (P <.05) animals. AF inducibility remained lower by week 15 in EARLY compared with CTL animals (32% ± 10% vs 91% ± 6%; P <.05). AF burden and inducibility were not significantly different between LATE and CTL animals. There were no structural differences among any groups. CONCLUSIONS SCS prolonged atrial effective refractory periods and reduced AF burden and inducibility in a canine AF model induced by TP. These data suggest that SCS may represent a treatment option for AF.

Impact of Practice Based Management of PA Pressures in 2000 Patients Implanted with the CardioMEMS Sensor

Background: Elevated pulmonary artery (PA) pressures in patients with heart failure are associated with a high risk for hospitalization and mortality. Recent clinical trial evidence demonstrated a direct relationship between lowering remotely monitored PA pressures and heart failure hospitalization risk reduction with a novel implantable PA pressure monitoring system (CardioMEMS HF System, St. Jude Medical). This study examines PA pressure changes in the first 2000 US patients implanted in general practice use. Methods: Deidentified data from the remote monitoring Merlin.net (St. Jude Medical) database were used to examine PA pressure trends from the first consecutive 2000 patients with at least 6 months of follow-up. Changes in PA pressures were evaluated with an area under the curve methodology to estimate the total sum increase or decrease in pressures (mm Hg-day) during the follow-up period relative to the baseline pressure. As a reference, the PA pressure trends were compared with the historic CHAMPION clinical trial (CardioMEMS Heart Sensor Allows Monitoring of Pressure to Improve Outcomes in New York Heart Association [NYHA] Functional Class III Heart Failure Patients). The area under the curve results are presented as mean±2 SE, and P values comparing the area under the curve of the general-use cohort with outcomes in the CHAMPION trial were computed by the t test with equal variance. Results: Patients were on average 70±12 years old; 60% were male; 34% had preserved ejection fraction; and patients were followed up for an average of 333±125 days. At implantation, the mean PA pressure for the general-use patients was 34.9±10.2 mm Hg compared with 31.3±10.9 mm Hg for CHAMPION treatment and 32.0±10.5 mm Hg for CHAMPION control groups. The general-use patients had an area under the curve of −32.8 mm Hg-day at the 1-month time mark, −156.2 mm Hg-day at the 3-month time mark, and −434.0 mm Hg-day after 6 months of hemodynamic guided care, which was significantly lower than the treatment group in the CHAMPION trial. Patients consistently transmitted pressure information with a median of 1.27 days between transmissions after 6 months. Conclusions: The first 2000 general-use patients managed with hemodynamic-guided heart failure care had higher PA pressures at baseline and experienced greater reduction in PA pressure over time compared with the pivotal CHAMPION clinical trial. These data demonstrate that general use of implantable hemodynamic technology in a nontrial setting leads to significant lowering of PA pressures.

Pulmonary artery pressure-guided heart failure management: US cost-effectiveness analyses using the results of the CHAMPION clinical trial

Haemodynamic‐guided heart failure (HF) management effectively reduces decompensation events and need for hospitalizations. The economic benefit of clinical improvement requires further study.

Improving the Efficiency of Heart Failure Care

Background Ambulatory pulmonary artery (PA) pressure-directed clinical management of Heart Failure (HF) patients has been shown to reduce HF hospitalizations; however the work flow associated with remote hemodynamic monitoring in such patients has not been studied. We performed a time and motion study in a group of patients with heart failure. Methods A non-interventional, single site “time and motion” study of usual care processes was conducted in the Heart Failure clinic of a 630-bed community hospital between July - October 2017. All enrolled patients were NYHA class III. Patients previously implanted with an ambulatory PA pressure sensor (CardioMEMSTM, Abbott; CMEM group), as well as sensor-eligible patients who had not previously received the implant (non-CMEM group), were recruited at a routine HF clinic visit. The usual care visit, for both CMEM and non-CMEM group, was observed from the time the patient arrived at the clinic to the time they left. The in-clinic observation was quantified based on the time spent in the prep area, exam room area, dictation, and scheduling desk. Primary reason for telephone calls made to CMEM group was captured. Results The HF clinic workflow was observed for 53 patients (n = 24 CMEM, n  =  29 non-CMEM). The mean clinic visit time were 48:55 ± 15:34 minutes for CMEM and 55:57 ± 21:42 minutes non-CMEM (p  =  0.07). 75% of the visit time was spent in the exam room with the provider. Telephone call duration was 5:47 ± 15:09 minutes (N = 92) with a median of 2:13 minutes of which, 52% were related to review of pulmonary artery pressures, 29% to HF monitoring, 12% to labs, and 3% to medication change. Conclusion This is the first characterization of the practical implications of utilizing remote hemodynamic monitoring. The additional time spent during follow-up calls was partially offset by shorter office visits. In addition, since most of the office time involved the provider (exam room) as opposed to nurse time (phone calls), the utilization of CardioMEMS™ may improve provider efficiency. The economic implications of remote hemodynamic management and office visits for HF patients can be studied based on these data.

Changes in pulmonary artery pressure before and after left ventricular assist device implantation in patients utilizing remote haemodynamic monitoring: Changes in PA pressures around LVAD implant

The time course of changes in pulmonary artery (PA) pressure due to left ventricular assist devices (LVADs) is not well understood. Here, we describe longitudinal haemodynamic trends during the peri‐LVAD implantation period in patients previously implanted with a remote monitoring PA pressure sensor.