Foley, Thomas A.

AbstractIntroductionThree‐dimensional (3D) prototyping is a novel technology which can be used to plan and guide complex procedures such as transcatheter mitral valve replacement (TMVR).MethodsEight patients with severe mitral annular calcification (MAC) underwent TMVR. 3D digital models with digital balloon expandable valves were created from pre‐procedure CT scans using dedicated software. Five models were printed. These models were used to assess prosthesis sizing, anchoring, expansion, paravalvular gaps, left ventricular outflow tract (LVOT) obstruction, and other potential procedure pitfalls. Results of 3D prototyping were then compared to post procedural imaging to determine how closely the achieved procedural result mirrored the 3D modeled result.Results3D prototyping simulated LVOT obstruction in one patient who developed it and in another patient who underwent alcohol septal ablation prior to TMVR. Valve sizing correlated with actual placed valve size in six out of the eight patients and more than mild paravalvular leak (PVL) was simulated in two of the three patients who had it. Patients who had mismatch between their modeled valve size and post‐procedural imaging were the ones that had anterior leaflet resection which could have altered valve sizing and PVL simulation. 3D printed model of one of the latter patients allowed modification of anterior leaflet to simulate surgical resection and was able to estimate the size and location of the PVL after inserting a valve stent into the physical model.Conclusion3D prototyping in TMVR for severe MAC is feasible for simulating valve sizing, apposition, expansion, PVL, and LVOT obstruction.

Background Atrial fibrillation (AF) is the most common sustained atrial arrhythmia. One potential target for ablation is left atrial (LA) scar (LAS) regions that may be the substrate for re-entry within the atria, thereby sustaining AF. Identification of LAS through LA delayed gadolinium enhancement (LADE) with MRI has been proposed. Objectives We sought to evaluate LADE in patients referred for catheter ablation of AF. Methods Prospective analysis was conducted of consecutive patients who underwent pulmonary vein antrum isolation (PVAI) ablation for AF at a single institution. Patients underwent LADE with MRI to determine LAS regions before ablation. MRI data were analysed independently in accordance with prespecified institutional protocol by two staff cardiac radiologists to whom patient outcomes were masked, and reports of LADE were documented. Where no initial consensus occurred regarding delayed enhancement (DE), a third staff cardiac radiologist independently reviewed the case and had the deciding vote. Results Of the 149 consecutive patients (mean (SD) age, 59 (9) years), AF was persistent in 64 (43%) and paroxysmal in 85 (57%); 45 (30%) had prior ablation. Only five patients (3%) had identifiable DE in LA walls (persistent AF, n=1; paroxysmal AF, n=4). LADE was present in two (4%) of the 45 patients with previous left PVAI. The presence of LADE was not associated with a higher recurrence rate of AF. Conclusions In contrast to previous studies, the finding of DE within LA walls was uncommon and, when present, did not correlate with AF type or risk of AF recurrence. It therefore is of unclear clinical significance.

PurposeInfarct mass as assessed by myocardial‐delayed enhancement imaging on cardiac magnetic resonance (CMR) and myocardial blood flow as assessed by real time myocardial perfusion echocardiography (RT‐MPE) have been shown to predict adverse events following ST elevation myocardial infarction (STEMI). There has been no published comparison of quantitative assessment using these modalities as predictors of clinical outcomes to date. We compared RT‐MPE with CMR for prediction of cardiac events in reperfused STEMI patients.Materials and MethodsConsecutive STEMI patients with early reperfusion were studied. RT‐MPE and CMR were performed. Perfusion score indices (PSIRT‐MPE and PSICMR) were calculated [sum of segmental perfusion scores/number of segments]. CMR infarct mass (g) and RT‐MPE myocardial blood flow (MBF dB/s) were quantified. Patients were followed for cardiac events (death, nonfatal MI, revascularization, angina, and heart failure).ResultsAll 27 patients (age 62±14; follow‐up 3.5±2.6 years) had thrombolysis in myocardial infarction (TIMI) grade 3 flow of infarct vessel. Cardiac events occurred in 17 (63%). Cardiac event patients had higher PSIRT‐MPE, PSICMR, infarct mass, and lower MBF. PSIRT‐MPE cutoff of 0.3 had an AUC of 0.856 (82% sensitivity, 70% specificity), while a PSICMR cutoff of 0.2 had an AUC of 0.765 (76% sensitivity, 60% specificity). Infarct mass and MBF were independent predictors of cardiac events after adjusting for risk factors (hazard ratios: 20.9 [95% CI 1.8–256] P=.02 and 8.1 [95% CI 1.5–78] P=.01, respectively).ConclusionsQuantitative RT‐MPE performed comparably to CMR for prediction of MACE in STEMI patients supporting a prognostic role for this noninvasive, bedside imaging method.