Implementation of a cardiac PET stress program: comparison of outcomes to the preceding SPECT era.

BACKGROUND: Cardiac positron emission testing (PET) is more accurate than single photon emission computed tomography (SPECT) at identifying coronary artery disease (CAD); however, the 2 modalities have not been thoroughly compared in a real-world setting. We conducted a retrospective analysis of 60-day catheterization outcomes and 1-year major adverse cardiovascular events (MACE) after the transition from a SPECT- to a PET-based myocardial perfusion imaging (MPI) program. METHODS: MPI patients at Intermountain Medical Center from January 2011-December 2012 (the SPECT era, n = 6,777) and January 2014-December 2015 (the PET era, n = 7,817) were studied. Outcomes studied were 60-day coronary angiography, high-grade obstructive CAD, left main/severe 3-vessel disease, revascularization, and 1-year MACE-revascularization (MACE-revasc; death, myocardial infarction [MI], or revascularization >60 days). RESULTS: Patients were 64 ± 13 years old; 54% were male and 90% were of European descent; and 57% represented a screening population (no prior MI, revascularization, or CAD). During the PET era, compared with the SPECT era, a higher percentage of patients underwent coronary angiography (13.2% vs. 9.7%, P < 0.0001), had high-grade obstructive CAD (10.5% vs. 6.9%, P < 0.0001), had left main or severe 3-vessel disease (3.0% vs. 2.3%, P = 0.012), and had coronary revascularization (56.7% vs. 47.1%, P = 0.0001). Similar catheterization outcomes were seen when restricted to the screening population. There was no difference in 1-year MACE-revasc (PET [5.8%] vs. SPECT [5.3%], P = 0.31). CONCLUSIONS: The PET-based MPI program resulted in improved identification of patients with high-grade obstructive CAD, as well as a larger percentage of revascularization, thus resulting in fewer patients undergoing coronary angiography without revascularization. FUNDING: This observational study was funded using internal departmental funds.

Real world MRI experience with nonconditional and conditional cardiac rhythm devices after MagnaSafe.

INTRODUCTION: The recent MagnaSafe Registry demonstrated safety of nonthoracic magnetic resonance imaging (MRI) with nonconditional cardiac implantable electronic devices (CIEDs). However, independent validation and extension to thoracic MRIs are needed. METHODS AND RESULTS: We prospectively examined 178 consecutive patients with CIEDs who underwent 212 MRI scans (62 with implantable cardioverter/defibrillators) for clinical reasons between February 2014 and August 2016. Scans were done in standard modes with a limit of 2 W/kg. Pacing modes were ODO or OVO for intrinsic rates > 40 and DOO or VOO for rates ≤ 40. Patients were cleared prescan by both radiology and cardiology, and pre- and postscan CIED interrogations were performed. Primary outcome events were death and generator or lead failure. Secondary events included battery voltage loss > 0.04 V, decrease in P wave voltage > 50% or R wave voltage > 25%, threshold increase of > 0.5 V, and impedance change > 50 Ω. Scan sites were 87 (41%) C-spine/head/neck, 28 (13%) T-spine/cardiac/shoulder (thoracic), 69 (33%) L-spine/abdomen/pelvis, and 28 (13%) lower extremity. No primary or secondary outcome events occurred, and no periscan disruption of pacing was noted. CONCLUSION: In a real-world MRI experience in patients with CIEDs representing a broad range of models, types, and scan sites (including thoracic scans), no adverse safety signals were noted. This experience validates and extends that of the large but inclusion-restricted MagnaSafe Registry, profiles MRI scanning in CIED patients in general clinical practice, and argues against replacing nonconditional with conditional devices when MRI is performed in a carefully controlled environment.