Comparison of cardiac magnetic resonance imaging and fluorodeoxyglucose positron emission tomography in the assessment of myocardial viability: meta-analysis and systematic review.

AIM: Contrast-enhanced cardiac magnetic resonance (Ce-CMR) and Fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) are frequently utilized in clinical practice to assess myocardial viability. However, studies evaluating direct comparison between Ce-CMR and FDG-PET have a smaller sample size, and no clear distinction between the two imaging modalities has been defined. To address this gap, we conducted a meta-analysis of studies comparing Ce-CMR and FDG-PET for the assessment of myocardial viability. METHODS: We searched PubMed, EMBASE, Scopus, and Web of Science databases from their inception to 4/20/2022 with search terms "viability" AND "heart diseases" AND "cardiac magnetic resonance imaging" AND "positron-emission tomography." We extracted patient characteristics, segment level viability assessment according to Ce-CMR and FDG-PET, and change in regional wall motion abnormalities (RWMA) at follow-up. RESULTS: We included four studies in the meta-analysis which provided viability assessment with Ce-CMR and FDG-PET in all patients and change in RWMA at follow-up. There were 82 patients among the four included studies, and 585 segments were compared for viability assessment. There were 59 (72%) males, and mean age was 65 years. The sensitivity (95% confidence interval-CI) and specificity (CI) of Ce-CMR for predicting myocardial recovery were 0.88 (0.66-0.96) and 0.64 (0.49-0.77), respectively. The sensitivity (CI) and specificity (CI) of FDG-PET for predicting myocardial recovery were 0.91 (0.63-0.99) and 0.67 (0.49-0.81), respectively. CONCLUSION: FDG-PET and Ce-CMR have comparable diagnostic parameters in myocardial viability assessment and are consistent with prior research.

Impact of Pre-Existing and New-Onset Atrial Fibrillation on Outcomes After Transcatheter Aortic Valve Replacement.

OBJECTIVES: This study sought to evaluate impact of new-onset and pre-existing atrial fibrillation (AF) on transcatheter aortic valve replacement (TAVR) long-term outcomes compared with patients without AF. BACKGROUND: Pre-existing and new-onset AF in patients undergoing TAVR are associated with poor outcomes. METHODS: The study identified 72,660 patients ≥65 years of age who underwent nonapical TAVR between 2014 and 2016 using Medicare inpatient claims. History of AF was defined by diagnoses on claims during the 3 years preceding the TAVR, and new-onset AF was defined as occurrence of AF during the TAVR admission or within 30 days after TAVR in a patient without prior history of AF. Outcomes included all-cause mortality, and readmission for bleeding, stroke, and heart failure (HF). RESULTS: Overall, 40.7% had pre-existing AF (n = 29,563) and 6.8% experienced new-onset AF (n = 2,948) after TAVR. Mean age was 81.3, 82.4, and 83.8 years in patients with no AF, pre-existing, and new-onset AF, respectively. Pre-existing AF patients had the highest burden of comorbidities. After follow-up of 73,732 person-years, mortality was higher with new-onset AF compared with pre-existing and no AF (29.7, 22.6, and 12.8 per 100 person-years, respectively; p < 0.001). After adjusting for patient characteristics and hospital TAVR volume, new-onset AF remained associated with higher mortality compared with no AF (adjusted hazard ratio: 2.068, 95% confidence interval [CI]: 1.92 to 2.20; p < 0.01) and pre-existing AF (adjusted hazard ratio: 1.35; 95% CI: 1.26 to 1.45; p < 0.01). In competing risk analysis, new-onset AF was associated with higher risk of bleeding (subdistribution hazard ratio [sHR]: 1.66; 95% CI: 1.48 to 1.86; p < 0.01), stroke (sHR: 1.92; 95% CI: 1.63 to 2.26; p < 0.01), and HF (sHR: 1.98; 95% CI: 1.81 to 2.16; p < 0.01) compared with pre-existing AF. CONCLUSIONS: In patients undergoing TAVR, new-onset AF is associated with increased risk of mortality and bleeding, stroke, and HF hospitalizations compared with pre-existing AF or no AF.

Role of diabetes and insulin use in the risk of stroke and acute myocardial infarction in patients with atrial fibrillation: A Medicare analysis.

BACKGROUND: Atrial fibrillation (AF) is associated with elevated risk for ischemic stroke and myocardial infarction (MI). The aim of the study is to assess the role of insulin use on the risk of stroke and MI in AF patients with diabetes. METHODS: We identified Medicare beneficiaries with new AF in 2011 to 2013. Primary outcomes were ischemic stroke and MI. Multivariate Cox regression models were used to assess the association between AF and time to stroke and MI. We adjusted for anticoagulant as a time-dependent covariate. RESULTS: Out of 798,592 AF patients, 53,212 (6.7%) were insulin-requiring diabetics (IRD), 250,214 (31.3%) were non-insulin requiring diabetics (NIRD) and 495,166 (62%) were non-diabetics (ND). IRD had a higher risk of stroke when compared to NIRD (adjusted HR: 1.15, 95% CI 1.10-1.21) and ND (aHR 1.24, 95% CI 1.18-1.31) (P < .01 for both). The risk of stroke was higher in NIRD compared to ND (aHR 1.08, 95% CI 1.05-1.12). For the outcome of MI, IRD had a higher risk compared to NIRD (aHR 1.24, 95% CI 1.18-1.31) and ND (aHR 1.46, 95% CI 1.38-1.54)]. NIRD had a higher risk compared to ND (aHR 1.17, 95% CI 1.13-1.22). Anticoagulation were most effective at preventing stroke in ND [0.72 (0.69-0.75)], and NIRD [0.88 (0.85-0.92)], but were not associated with significant reduction in stroke in IRD [0.96 (0.89-1.04)]. CONCLUSION: There is an incremental risk of ischemic stroke and MI from non-diabetics to non-insulin diabetics with the highest risk in insulin users. Protective effect of anticoagulation is attenuated with insulin use.

Sex-Specific Associations of Oral Anticoagulant Use and Cardiovascular Outcomes in Patients With Atrial Fibrillation.

BACKGROUND: Sex-specific effectiveness of rivaroxaban (RIVA), dabigatran (DABI), and warfarin in reducing myocardial infarction (MI), heart failure (HF), and all-cause mortality among patients with atrial fibrillation are not known. We assessed sex-specific associations of RIVA, DABI, or warfarin use with the risk of MI, HF, and all-cause mortality among patients with atrial fibrillation. METHODS AND RESULTS: Medicare beneficiaries (men: 65 734 [44.8%], women: 81 135 [55.2%]) with atrial fibrillation who initiated oral anticoagulants formed the study cohort. Inpatient admissions for MI, HF, and all-cause mortality were compared between the 3 drugs separately for men and women using 3-way propensity-matched samples. In men, RIVA use was associated with a reduced risk of MI admissions compared with warfarin use (hazard ratio [95% confidence interval (CI): 0.59 [0.38-0.91]), with a trend towards reduced risk compared with DABI use (0.67 [0.44-1.01]). In women, there were no significant differences in the risk of MI admissions across all 3 anticoagulants. In both sexes, RIVA use and DABI use were associated with reduced risk of HF admissions (men: RIVA; 0.75 [0.63-0.89], DABI; 0.81 [0.69-0.96]) (women: RIVA; 0.64 [0.56-0.74], DABI; 0.73 [0.63-0.83]) and all-cause mortality (men: RIVA; 0.66 [0.53-0.81], DABI; 0.75 [0.61-0.93]) (women: RIVA; 0.76 [0.63-0.91], DABI; 0.77 [0.64-0.93]) compared with warfarin use. CONCLUSIONS: RIVA use and DABI use when compared with warfarin use was associated with a reduced risk of HF admissions and all-cause mortality in both sexes. However, reduced risk of MI admissions noted with RIVA use appears to be limited to men.

Sex-Specific Comparative Effectiveness of Oral Anticoagulants in Elderly Patients With Newly Diagnosed Atrial Fibrillation.

BACKGROUND: Sex-specific comparative effectiveness of direct oral anticoagulants among patients with nonvalvular atrial fibrillation is not known. Via this retrospective cohort study, we assessed the sex-specific, comparative effectiveness of direct oral anticoagulants (rivaroxaban and dabigatran), compared to each other and to warfarin among patients with atrial fibrillation. METHODS AND RESULTS: Elderly (aged ≥66 years) Medicare beneficiaries enrolled in Medicare Part D benefit plan from November 2011 to October 2013 with newly diagnosed atrial fibrillation formed the study cohort (65 734 [44.8%] men and 81 137 [55.2%] women). Primary outcomes of inpatient admissions for ischemic strokes and major bleeding were compared across the 3 drugs (rivaroxaban: 20 mg QD, dabigatran: 150 mg BID, or warfarin) using 3-way propensity-matched samples. In men, rivaroxaban use decreased stroke risk when compared with warfarin use (hazard ratio, 0.69; 95% confidence interval, 0.48-0.99; P=0.048) and dabigatran use (hazard ratio, 0.66; 95% confidence interval, 0.45-0.96; P=0.029) and was associated with a similar risk of any major bleeding when compared with warfarin and dabigatran. In women, although ischemic stroke risk was similar in the 3 anticoagulant groups, rivaroxaban use significantly increased the risk for any major bleeding when compared with warfarin (hazard ratio, 1.20; 95% confidence interval, 1.03-1.42; P=0.021) and dabigatran (hazard ratio, 1.27; 95% confidence interval, 1.09-1.48; P=0.011). CONCLUSIONS: The reduced risk of ischemic stroke in patients taking rivaroxaban, compared with dabigatran and warfarin, seems to be limited to men, whereas the higher risk of bleeding seems to be limited to women.

Design and rationale of the assessment of proper physiologic response with rate adaptive pacing driven by minute ventilation or accelerometer (APPROPRIATE) trial.

Rate-adaptive sensors are designed to restore a physiologic heart rate response to activity, in particular for patients that have chronotropic incompetence (CI). Limited data exist comparing two primary types of sensors; an accelerometer (XL) sensor which detects activity or motion and a minute ventilation (MV) sensor, which detects the product of respiration rate and tidal volume. The APPROPRIATE study will evaluate the MV sensor compared with the XL sensor for superiority in improving functional capacity (peak VO(2)) in pacemaker patients that have CI. This study is a double-blind, randomized, two-arm trial that will enroll approximately 1,000 pacemaker patients. Patients will complete a 6-min walk test at the 2-week visit to screen for potential CI. Those projected to have CI will advance to a 1-month visit. At the 1-month visit, final determination of CI will be done by completing a peak exercise treadmill test while the pacemaker is programmed to DDDR with the device sensors set to passive. Patients failing to meet the study criteria for CI will not continue further in the trial. Patients that demonstrate CI will be randomized to program their rate-adaptive sensors to either MV or XL in a 1:1 ratio. The rate-adaptive sensor will be optimized for each patient using a short walk to determine the appropriate response factor. At a 2-month visit, patients will complete a CPX test with the rate-adaptive sensors in their randomized setting.