Use of healthcare claims to validate the Prevention of Arrhythmia Device Infection Trial cardiac implantable electronic device infection risk score.

AIM: The Prevention of Arrhythmia Device Infection Trial (PADIT) infection risk score, developed based on a large prospectively collected data set, identified five independent predictors of cardiac implantable electronic device (CIED) infection. We performed an independent validation of the risk score in a data set extracted from U.S. healthcare claims. METHODS AND RESULTS: Retrospective identification of index CIED procedures among patients aged ≥18 years with at least one record of a CIED procedure between January 2011 and September 2014 in a U.S health claims database. PADIT risk factors and major CIED infections (with system removal, invasive procedure without system removal, or infection-attributable death) were identified through diagnosis and procedure codes. The data set was randomized by PADIT score into Data Set A (60%) and Data Set B (40%). A frailty model allowing multiple procedures per patient was fit using Data Set A, with PADIT score as the only predictor, excluding patients with prior CIED infection. A data set of 54 042 index procedures among 51 623 patients with 574 infections was extracted. Among patients with no history of prior CIED infection, a 1 unit increase in the PADIT score was associated with a relative 28% increase in infection risk. Prior CIED infection was associated with significant incremental predictive value (HR 5.66, P < 0.0001) after adjusting for PADIT score. A Harrell's C-statistic for the PADIT score and history of prior CIED infection was 0.76. CONCLUSION: The PADIT risk score predicts increased CIED infection risk, identifying higher risk patients that could potentially benefit from targeted interventions to reduce the risk of CIED infection. Prior CIED infection confers incremental predictive value to the PADIT score.

Ventricular tachycardia induced by a backup pacing stimulus in a patient with a dual chamber pacemaker with AutoCapture.

Manufacturers of cardiac implantable electronic devices have incorporated automatic features to allow for remote monitoring, improve device longevity, and additional safety. Algorithms to automatically measure capture threshold and adjust output to preserve battery life are one such feature. Automatic features may occasionally result in unexpected or undesirable clinical outcomes. We report on a patient who developed ventricular tachycardia inadvertently induced by the AutoCapture. feature of an Abbott/St. Jude Medical (SJM) pacemaker.

Atrial fibrillation post central retinal artery occlusion: Role of implantable loop recorders.

OBJECTIVE: This study evaluated the risk of subclinical atrial fibrillation (AF) in patients with central retinal artery occlusion (CRAO) compared to those with cryptogenic stroke using implantable loop recorders (ILR). METHODS: We conducted a retrospective analysis of 273 consecutive patients who had ILRs inserted at our institution for either cryptogenic stroke (n = 227) or CRAO (n = 46). Our primary endpoint was a time to event analysis for the new diagnosis of AF by ILR. Univariable and multivariable Cox proportional hazard models were used to determine the predictors of time-to-AF. RESULTS: A total of 64 patients were found to have newly diagnosed AF by remote monitoring of the ILR. AF was detected in 57 of 227 (25%) cryptogenic stroke patients by the end of a maximum 5.1 years follow-up and in seven of 46 (15%) CRAO patients by the end of a maximum 3.6 years follow-up (P = .215, log-rank test). The Kaplan-Meier estimates for freedom from AF was 59.4% for CRAO and 66.6% for cryptogenic stroke (P = NS, log-rank test). Baseline variables predicting AF included older patients, higher CHADS2 VASC score, longer PR interval on initial EKG evaluation, and mitral annular calcification on transthoracic echocardiogram. CONCLUSIONS: Patients with CRAO are at risk for subclinical AF, similar to those with cryptogenic stroke. Long-term monitoring to detect AF may lead to changes in pharmacotherapy to reduce the risk for subsequent stroke.

Cardiovascular implantable electronic device infections due to enterococcal species: Clinical features, management, and outcomes.

BACKGROUND: Enterococcal cardiovascular implantable electronic device (CIED) infections are not well characterized. METHODS: Data from the Multicenter Electrophysiologic Device Infection Cohort, a prospective study of CIED infections, were used for descriptive analysis of adults with enterococcal CIED infections. RESULTS: Of 433 patients, 21 (4.8%) had enterococcal CIED infection. Median age was 71 years. Twelve patients (57%) had permanent pacemakers, five (24%) implantable cardioverter defibrillators, and four (19%) biventricular devices. Median time from last procedure to infection was 570 days. CIED-related bloodstream infections occurred in three patients (14%) and 18 (86%) had infective endocarditis (IE), 14 (78%) of which were definite by the modified Duke criteria. IE cases were classified as follows: valvular IE, four; lead IE, eight; both valve and lead IE, six. Vegetations were demonstrated by transesophageal echocardiography in 17 patients (81%). Blood cultures were positive in 19/19 patients with confirmed results. The most common antimicrobial regimen was penicillin plus an aminoglycoside (33%). Antibiotics were given for a median of 43 days. Only 14 patients (67%) underwent device removal. There was one death during the index hospitalization with four additional deaths within 6 months (overall mortality 24%). There were no relapses. CONCLUSIONS: Enterococci caused 4.8% of CIED infections in our cohort. Based on the late onset after device placement or manipulation, most infections were likely hematogenous in origin. IE was the most common infection syndrome. Only 67% of patients underwent device removal. At 6 months follow-up, no CIED infection relapses had occurred, but overall mortality was 24%.

Treatment patterns, costs, and mortality among Medicare beneficiaries with CIED infection.

BACKGROUND: Cardiac implantable electronic device (CIED) infection is a serious adverse event, but there are limited contemporary real-world data on treatment pathways and associated costs in the Medicare population following diagnosis of CIED infection. Hence, this study evaluates postinfection treatment pathways and associated healthcare expenditures and mortality among Medicare fee-for-service beneficiaries with CIED infection. METHODS: Retrospective cohort analysis of 5,401 beneficiaries who developed a device-related infection in the year following implantation/upgraded CIED (1/1/2010-12/31/2012). Patients were followed-up to 12 months/death following diagnosis of infection and were divided into mutually exclusive groups based on whether they underwent CIED system removal (Group I), or no CIED system intervention (Group II; IIA with or IIB without infection hospitalization). All-cause healthcare resource utilization/expenditures were also measured. RESULTS: In the year following infection, 64.1% of patients underwent device extraction, of who 2,109 (39.0%) had their device replaced (Group IA) and 1,355 (25.1%) had their device extracted without replacement (Group IB); 62.2% of patients were hospitalized and 25.3% of patients died. Mean Medicare payments-per-patient for facility-based services by group were: IA = $62,638 (standard deviation [SD]: $46,830), IB = $50,079 (SD: $45,006), IIA = $77,397 (SD: $79,130), and IIB = $22,856 (SD: $31,167). CONCLUSIONS: Hospitalizations were the largest cost driver; infection-related costs, including cost of extraction/replacement, accounted for >50% of expenditures for patients with surgical/hospital intervention. Management of CIED infection in Medicare beneficiaries is associated with high healthcare expenditures in the year following infection. Additional measures to prevent device infection are needed to improve the outcomes and reduce costs in these patients.

Attempted salvage of infected cardiovascular implantable electronic devices: Are there clinical factors that predict success?

BACKGROUND: Published guidelines mandate complete device removal in cases of cardiovascular implantable electronic device (CIED) infection. Clinical predictors of successful salvage of infected CIEDs have not been defined. METHODS: Data from the Multicenter Electrophysiologic Device Infection Collaboration, a prospective, observational, multinational cohort study of CIED infection, were used to investigate whether clinical predictors of successful salvage of infected devices could be identified. RESULTS: Of 433 adult patients with CIED infections, 306 (71%) underwent immediate device explantation. Medical management with device retention and antimicrobial therapy was initially attempted in 127 patients (29%). "Early failure" of attempted salvage occurred in 74 patients (58%) who subsequently underwent device explantation during the index hospitalization. The remaining 53 patients (42%) in the attempted salvage group retained their CIED. Twenty-six (49%) had resolution of CIED infection (successful salvage group) whereas 27 patients (51%) experienced "late" salvage failure. Upon comparing the salvage failure group, early and late (N = 101), to the group experiencing successful salvage of an infected CIED (N = 26), no clinical or laboratory predictors of successful salvage were identified. However, by univariate analysis, coagulase-negative staphylococci as infecting pathogens (P = 0.0439) and the presence of a lead vegetation (P = 0.024) were associated with overall failed salvage. CONCLUSIONS: In patients with definite CIED infections, clinical and laboratory variables cannot predict successful device salvage. Until new data are forthcoming, device explantation should remain a mandatory and early management intervention in patients with CIED infection in keeping with existing expert guidelines unless medical contraindications exist or patients refuse device removal.

Ampere Hour as a Predictor of Cardiac Resynchronization Defibrillator Pulse Generator Battery Longevity: A Multicenter Study.

BACKGROUND: Cardiac resynchronization defibrillator (CRT-D) devices improve survival for New York Heart Association classes II-IV systolic heart failure patients with QRS > 120 ms and left ventricular ejection fraction < 35%. A limitation of 100% CRT pacing is excess battery depletion and pulse generator (PG) replacement compared to VVI or dual-chamber systems. Ampere hour (Ah) measures PG battery capacity and may predict CRT-D device longevity. METHODS: We performed a multicenter retrospective study of all CRT-D devices implanted at our centers from August 1, 2008 to December 31, 2010. Analysis was performed for survival to elective replacement indicator (ERI) between 1.0 Ah, 1.4 Ah, and 2.0 Ah devices, per manufacturers' specifications. RESULTS: One thousand three hundred and two patients were studied through December 31, 2014. Patients were followed for an average of 3.0 ± 1.3 years (794 1.0 Ah, 322 2.0 Ah, and 186 1.4 Ah devices under study). CRT-D generator ERI occurred in 13.5% of 1.0 Ah systems (107 out of 794), versus 3.8% in 1.4 Ah (seven out of 186), and 0.3% in 2.0 Ah devices (one out of 322) over mean follow-up of 3.0 years. Odds ratio (OR) for reaching ERI with 1.0 Ah device versus 1.4 Ah or 2.0 Ah was 9.73, P < 0.0001. Univariate predictors for ERI included 1.0 Ah device and LV pacing output >3V @ 1 ms (OR: 3.74, P < 0.001). LV impedance >1,000 ohms predicted improved device survival (OR: 0.38, P = 0.0025). CONCLUSIONS: CRT-D battery capacity measured by Ah is a strong predictor of survival to ERI for modern systems. Further study on cost and morbidity associated with early PG change in 1.0 Ah systems is warranted.

Variability in clinical features of early versus late cardiovascular implantable electronic device pocket infections.

BACKGROUND: Cardiovascular implantable electronic device (CIED) pocket infections are often related to recent CIED placement or manipulation, but these infections are not well characterized. The clinical presentation of CIED pocket infection, based on temporal onset related to last CIED procedure, deserves further study. METHODS: The MEDIC (Multicenter Electrophysiologic Device Infection Cohort) prospectively enrolled subjects with CIED infection. Subjects were stratified into those whose infection occurred <12 months (early) or ≥ 12 months (late) since their last CIED-related procedure. RESULTS: There were 132 subjects in the early group and 106 in the late group. There were more females (P = 0.009) and anticoagulation use (P = 0.039) in the early group. Subjects with early infections were more likely to have had a generator change or lead addition as their last procedure (P = 0.03) and had more prior CIED procedures (P = 0.023). Early infections were more likely to present with pocket erythema (P < 0.001), swelling (P < 0.001), and pain (P = 0.007). Late infections were more likely to have pocket erosion (P = 0.005) and valvular vegetations (P = 0.009). In bacteremic subjects, early infections were more likely healthcare-associated (P < 0.001). In-hospital and 6-month mortality were equivalent. CONCLUSION: A total of 45% of patients with CIED pocket infection presented >12 months following their last CIED-related procedure. Patients with early infection were more likely to be female, on anticoagulation, and present with localized inflammation, whereas those with late infection were more likely to have CIED erosion or valvular endocarditis.