Safety of regadenoson positron emission tomography stress testing in orthotopic heart transplant patients.

OBJECTIVES: We sought to determine the safety of regadenoson (REG) stress testing in patients who have undergone orthotopic heart transplantation (OHT). BACKGROUND: Routine screening for cardiac allograft vasculopathy (CAV) is necessary after OHT. Adenosine stress is contraindicated after heart transplantation due to supersensitivity in denervated hearts. Safety of regadenoson stress following OHT has not been well studied. METHODS: We retrospectively reviewed data from OHT patients (N = 123) who were referred to REG stress testing. Medical records were reviewed to determine hemodynamic and ECG response to regadenoson and to identify adverse reactions. RESULTS: No serious adverse events occurred. No life-threatening arrhythmias or hemodynamic changes occurred. Common side-effects related to regadenoson were observed, dyspnea being the most frequent (66.7%). On average the heart rate rose from 82.8 ± 12 to 95.7 ± 13.4 bpm (P < 0.001), systolic blood pressure decreased from 138.7 ± 20.9 to 115.9 ± 23.9 mmHg (P < 0.001) and mean arterial pressure decreased from 103.5 ± 14.1 to 84.72 ± 15.90 mmHg (P < 0.001) during stress protocol. There was no sustained ventricular tachycardia, ventricular fibrillation, or second-or third-degree atrioventricular block. CONCLUSION: Regadenoson stress testing appears to be well tolerated and safe in OHT patients.

Adverse neurologic events in patients bridged with long-term mechanical circulatory support: A device-specific comparative analysis.

BACKGROUND: Neurologic complications are among the principal causes of morbidity and mortality after continuous-flow left ventricular assist device (CF-LVAD) implantation. The aim of this study was to describe a focused "real-world" multicenter comparison of neurologic outcomes between HeartMate II (HMII) and HeartWare HVAD CF-LVAD recipients. METHODS: Between March 2009 and October 2014, 497 patients underwent primary CF-LVAD implantation as a bridge to transplantation at centers included in the Mechanical Circulatory Support Research Network; 314 patients (63%) received HMII, and 183 patients (37%) received HVAD. Ischemic cerebrovascular accident, hemorrhagic cerebrovascular accident, and transient ischemic attack were the neurologic outcomes assessed. RESULTS: Median follow-up time for HMII recipients was 0.95 years (0.48, 1.85, range) and for HVAD recipients was 0.44 years (0.19, 0.97, range) (p < 0.001). HMII recipients had significantly fewer neurologic events per patient year for ischemic cerebrovascular accident (0.071) and transient ischemic attack (0.012) compared with HVAD recipients (0.157 and 0.072, respectively). Univariate analysis showed that 51 HMII recipients (16%) had any neurologic event, whereas 34 HVAD recipients (19%) had any neurologic event (p = 0.504). After adjusting for pre-specified covariates (device type, age, sex, atrial fibrillation, diabetes, and Interagency Registry for Mechanically Assisted Circulatory Support profile), multivariable analysis showed only advanced age was able to predict neurologic events (p = 0.02). Neurologic events were comparable between HMII and HVAD recipients after multivariable analysis. CONCLUSIONS: CF-LVAD placement incurs a low but significant risk of neurologic complications in patients receiving CF-LVADs as a bridge to transplantation. Advancing age is a risk factor for any adverse neurologic outcome. This multicenter analysis demonstrated comparable hazard of adverse neurologic events among patients implanted with HMII or HVAD.

Considerations on afterload management for patients with centrifugal ventricular assist devices.

This case report illustrates the challenges in managing patients with centrifugal ventricular assist devices (VADs). As these devices have evolved, their physical properties have changed, impacting patient management. Levitated centrifugal pumps have a non-linear response to afterloads. The device output will decrease significantly in the presence of high systemic vascular resistance. Blood pressure control is integral to the management of patients in the immediate and later postoperative period.

Predictors of death and transplant in patients with a mechanical circulatory support device: a multi-institutional study.

BACKGROUND: INTERMACS is a registry of FDA-approved durable mechanical circulatory support (MCS) devices used for the strategies of destination therapy (DT) and bridge to transplantation (BTT) or recovery. This study identifies predictors for death and transplantation based on initial results from INTERMACS. METHODS: From June 23, 2006 to December 31, 2007, 420 patients from 75 institutions were prospectively entered into the INTERMACS database in which pre-implant data, indication for MCS device use, adverse events, demographics, hemodynamics, laboratory values and outcomes were recorded. Using competing outcomes methodology, risk factors were identified for the events of death and transplantation. RESULTS: The devices included 314 left ventricular assist devices (LVADs), 5 right VADs (RVADs), 77 biventricular VADs (biVADs) and 24 total artificial hearts (TAHs) for a total of 497 pumps in 420 patients. Among the BTT patients at 6 months, 33% were alive with a device in place, 42% were transplanted, 22% had died, and 3% were explanted for recovery. Among the DT patients at 6 months, 68% were alive with a device in place, 5% were transplanted, 25% had died, and 2% were explanted for recovery. The risk factors identified for death across all patient groups include older age (relative risk [RR] = 1.41, p < 0.001), ascites (RR = 2.04, p = 0.003), increased bilirubin (RR = 1.49, p < 0.05) and INTERMACS Level 1 (cardiogenic shock) (RR = 1.59, p = 0.02). The most common causes of death were central nervous system (CNS) event (18.3% of deaths), multiple-organ failure (16.4%) and cardiac cause (right ventricular failure and arrhythmias, 15.4%). CONCLUSIONS: Cardiogenic shock, advanced age and severe right heart failure manifested as ascites or increased bilirubin are risk factors for death after MCS therapy. BTT patients who require biVAD support have a transplant rate similar to that of LVAD-only patients, but their mortality at 6 and 12 months exceeds that of LVAD-only patients. Consideration should be given to MCS referral before the sequelae of right ventricular failure dominate the advanced heart failure syndrome.

Physiologic and pathologic changes in patients with continuous-flow ventricular assist devices.

The clinical use of the newer continuous-flow pumps for mechanical circulatory support have resulted in superior outcomes including significantly reduced complication rates with improved durability over first generation pulsatile design pumps. However, as with all new technology, the newer LVADs have introduced a different set of management issues, as well as a unique risk profile into the mechanical circulatory support arena that were previously absent or unimportant with pulsatile LVADs. These include the effects of continuous flow on the systemic circulation and end-organ function, risk of thromboembolism, and pump thrombosis related to contact bearings in the blood path, the possible increased incidence of gastrointestinal bleeding, and ventricular arrhythmias, as well as alterations in the unloading characteristics of continuous-flow devices. This manuscript overviews the physiologic and pathologic effects that are associated with continuous-flow pumps and their unique management issues and complications.