Dynamic Myocardial Perfusion CT for the Detection of Hemodynamically Significant Coronary Artery Disease

OBJECTIVES In this international, multicenter study, using third-generation dual-source computed tomography (CT), we investigated the diagnostic performance of dynamic stress CT myocardial perfusion imaging (CT-MPI) in addition to coronary CT angiography (CTA) compared to invasive coronary angiography (ICA) and invasive fractional flow reserve (FFR). BACKGROUND CT-MPI combined with coronary CTA integrates coronary artery anatomy with inducible myocardial ischemia, showing promising results for the diagnosis of hemodynamically significant coronary artery disease in single-center studies. METHODS At 9 centers in Europe, Japan, and the United States, 132 patients scheduled for ICA were enrolled; 114 patients successfully completed coronary CTA, adenosine-stress dynamic CT-MPI, and ICA. Invasive FFR was performed in vessels with 25% to 90% stenosis. Data were analyzed by independent core laboratories. For the primary analysis, for each coronary artery the presence of hemodynamically significant obstruction was interpreted by coronary CTA with CT-MPI compared to coronary CTA alone, using an FFR of ≤0.80 and angiographic severity as reference. Territorial absolute myocardial blood flow (MBF) and relative MBF were compared using C-statistics. RESULTS ICA and FFR identified hemodynamically significant stenoses in 74 of 289 coronary vessels (26%). Coronary CTA with ≥50% stenosis demonstrated a per-vessel sensitivity, specificity, and accuracy for the detection of hemodynamically significant stenosis of 96% (95% CI: 91-100), 72% (95% CI: 66-78), and 78% (95% CI: 73-83), respectively. Coronary CTA with CT-MPI showed a lower sensitivity (84%; 95% CI: 75-92) but higher specificity (89%; 95% CI: 85-93) and accuracy (88%; 95% CI: 84-92). The areas under the receiver-operating characteristic curve of absolute MBF and relative MBF were 0.79 (95% CI: 0.71-0.86) and 0.82 (95% CI: 0.74-0.88), respectively. The median dose-length product of CT-MPI and coronary CTA were 313 mGy·cm and 138 mGy·cm, respectively. CONCLUSIONS Dynamic CT-MPI offers incremental diagnostic value over coronary CTA alone for the identification of hemodynamically significant coronary artery disease. Generalized results from this multicenter study encourage broader consideration of dynamic CT-MPI in clinical practice. (Dynamic Stress Perfusion CT for Detection of Inducible Myocardial Ischemia [SPECIFIC]; NCT02810795)

Transapical Mitral Valve Replacement: 1-Year Results of the Real-World Tendyne European Experience Registry.

BACKGROUND Early studies of the Tendyne transcatheter mitral valve replacement (TMVR) showed promising results in a small selective cohort. OBJECTIVES The authors present 1-year data from the currently largest commercial, real-world cohort originating from the investigator-initiated TENDER (Tendyne European Experience) registry. METHODS All patients from the TENDER registry eligible for 1-year follow-up were included. The primary safety endpoint was 1-year cardiovascular mortality. Primary performance endpoint was reduction of mitral regurgitation (MR) up to 1 year. RESULTS Among 195 eligible patients undergoing TMVR (median age 77 years [Q1-Q3: 71-81 years], 60% men, median Society of Thoracic Surgeons Predicted Risk of Mortality 5.6% [Q1-Q3: 3.6%-8.9%], 81% in NYHA functional class III or IV, 94% with MR 3+/4+), 31% had "real-world" indications for TMVR (severe mitral annular calcification, prior mitral valve treatment, or others) outside of the instructions for use. The technical success rate was 95%. The cardiovascular mortality rate was 7% at 30 day and 17% at 1 year (all-cause mortality rates were 9% and 29%, respectively). Reintervention or surgery following discharge was 4%, while rates of heart failure hospitalization reduced from 68% in the preceding year to 25% during 1-year follow-up. Durable MR reduction to ≤1+ was achieved in 98% of patients, and at 1 year, 83% were in NYHA functional class I or II. There was no difference in survival and major adverse events between on-label use and "real-world" indications up to 1 year. CONCLUSIONS This large, real-world, observational registry reports high technical success, durable and complete MR elimination, significant clinical benefits, and a 1-year cardiovascular mortality rate of 17% after Tendyne TMVR. Outcomes were comparable between on-label use and "real-world" indications, offering a safe and efficacious treatment option for patients without alternative treatments. (Tendyne European Experience Registry [TENDER]; NCT04898335)

Transapical mitral valve implantation for treatment of symptomatic mitral valve disease: a real-world multicentre experience.

AIMS Transcatheter mitral valve implantation (TMVI) is a new treatment option for patients with symptomatic mitral valve (MV) disease. Real-world data have not yet been reported. This study aimed to assess procedural and 30-day outcomes of TMVI in a real-world patient cohort. METHOD AND RESULTS All consecutive patients undergoing implantation of a transapically delivered self-expanding valve at 26 European centres from January 2020 to April 2021 were included in this retrospective observational registry. Among 108 surgical high-risk patients included (43% female, mean age 75 ± 7 years, mean STS-PROM 7.2 ± 5.3%), 25% was treated for an off-label indication (e.g. previous MV intervention or surgery, mitral stenosis, mitral annular calcification). Patients were highly symptomatic (New York Heart Association [NYHA] functional class III/IV in 86%) and mitral regurgitation (MR) was graded 3+/4+ in 95% (38% primary, 37% secondary, and 25% mixed aetiology). Technical success rate was 96%, and MR reduction to ≤1+ was achieved in all patients with successful implantation. There were two procedural deaths and 30-day all-cause mortality was 12%. At early clinical follow-up, MR reduction was sustained and there were significant reductions of pulmonary pressure (systolic pulmonary artery pressure 52 vs. 42 mmHg, p < 0.001), and tricuspid regurgitation severity (p = 0.013). Heart failure symptoms improved significantly (73% in NYHA class I/II, p < 0.001). Procedural success rate according to MVARC criteria was 80% and was not different in patients treated for an off-label indication (74% vs. 81% for off- vs. on-label, p = 0.41). CONCLUSION In a real-world patient population, TMVI has a high technical and procedural success rate with efficient and durable MR reduction and symptomatic improvement

Magnetic resonance phase contrast velocity mapping for flow quantification in irregular heart rhythms using radial k-space ultrashort echo time imaging

Background Phase contrast velocity mapping sequences utilising ultrashort echo time (UTE) radial k-space sequences have been used to reduce intravoxel dephasing at high velocities. We evaluated the accuracy of the UTE flow sequence for mitral regurgitation (MR) quantification, including patients with atrial fibrillation. Methods Forty patients underwent cardiac MRI for indirect MR quantification by assessment of aortic flow using a UTE phase contrast sequence (TE 0.65 ms) combined with left ventricular stroke volume. Retrospective ECG-gating was used in sinus rhythm (30 patients), prospective ECG-triggering in atrial fibrillation (10). MR was also quantified by a standard phase contrast sequence (TE 2.85 ms, standard flow method) and by comparing stroke volumes (volumetric method). Results UTE flow-derived MR measurement showed modest agreement in sinus rhythm (95% limits of agreement: ±38.2 ml; ±29.8%) and atrial fibrillation (±33.7 ml; ±30.3%) compared to standard flow assessment. There was little systematic bias in sinus rhythm (mean offset −4.4 ml /−3.5% compared to standard flow assessment), but a slight bias towards greater regurgitation in atrial fibrillation (+15.2 ml /+14.0%). There were wider limits of agreement between the UTE flow method and volumetric method than between the regular flow method and the volumetric method in sinus rhythm (±48.4 ml; ±36.4%; mean offset: −12.2 ml /−9.0%) and similar limits of agreement in atrial fibrillation (±29.6 ml; 25.8%; +12.0 ml /+10.3%). Conclusions UTE flow imaging is inferior to conventional flow techniques for MR assessment in patients with sinus rhythm as well as atrial fibrillation. However, the number of atrial fibrillation patients in this initial study is small