Regional variation in technetium pyrophosphate (PYP) uptake in transthyretin cardiac amyloidosis (ATTR-CA) and concomitant myocardial infarction: A case series.

- Diffuse and patchy myocardial uptake of Tc-99m PYP is well established in cases of ATTR-CA. - Chronic myocardial infarction leads to regional myocardial thinning and lack of vascular supply can present as regional sparing 'cold spot' on Tc-99m PYP imaging. - The absence of Tc-99m PYP uptake in vascular regions should raise the possibility of underlying scar.

Five-Year Outcomes of Transcatheter or Surgical Aortic-Valve Replacement.

BACKGROUND: There are scant data on long-term clinical outcomes and bioprosthetic-valve function after transcatheter aortic-valve replacement (TAVR) as compared with surgical aortic-valve replacement in patients with severe aortic stenosis and intermediate surgical risk. METHODS: We enrolled 2032 intermediate-risk patients with severe, symptomatic aortic stenosis at 57 centers. Patients were stratified according to intended transfemoral or transthoracic access (76.3% and 23.7%, respectively) and were randomly assigned to undergo either TAVR or surgical replacement. Clinical, echocardiographic, and health-status outcomes were followed for 5 years. The primary end point was death from any cause or disabling stroke. RESULTS: At 5 years, there was no significant difference in the incidence of death from any cause or disabling stroke between the TAVR group and the surgery group (47.9% and 43.4%, respectively; hazard ratio, 1.09; 95% confidence interval [CI], 0.95 to 1.25; P = 0.21). Results were similar for the transfemoral-access cohort (44.5% and 42.0%, respectively; hazard ratio, 1.02; 95% CI, 0.87 to 1.20), but the incidence of death or disabling stroke was higher after TAVR than after surgery in the transthoracic-access cohort (59.3% vs. 48.3%; hazard ratio, 1.32; 95% CI, 1.02 to 1.71). At 5 years, more patients in the TAVR group than in the surgery group had at least mild paravalvular aortic regurgitation (33.3% vs. 6.3%). Repeat hospitalizations were more frequent after TAVR than after surgery (33.3% vs. 25.2%), as were aortic-valve reinterventions (3.2% vs. 0.8%). Improvement in health status at 5 years was similar for TAVR and surgery. CONCLUSIONS: Among patients with aortic stenosis who were at intermediate surgical risk, there was no significant difference in the incidence of death or disabling stroke at 5 years after TAVR as compared with surgical aortic-valve replacement. (Funded by Edwards Lifesciences; PARTNER 2 ClinicalTrials.gov number, NCT01314313.).

Anticoagulation after pulmonary vein isolation for atrial fibrillation: Associations with CHA2DS2-VASc score, sex, and rhythm.

Guidelines recommend using the CHA2DS2-VASc score to determine anticoagulation decisions in atrial fibrillation (AF) patients, including those who undergo pulmonary vein isolation (PVI), however this may not consistently occur in the real-world setting because of other clinical factors. We sought to evaluate the anticoagulation prescription rates patterns in AF patients 1 year PVI at our institution. Consecutive AF patients undergoing PVI in our prospective registry during 2014-2018 who were alive at 1-year post-PVI were studied. Anticoagulation prescription rates at this time-point were adjudicated, and correlated to CHA2DS2-VASc score, sex, and heart rhythm status at 1 year. Amongst 4596 patients undergoing PVI, mean age was 64.2 ± 10.0 years, 1328 (28.9%) were female, and based on CHA2DS2-VASc score anticoagulation was not indicated, can be considered and indicated in 872 (19.0%), 1183 (25.7%), and 2541 (55.3%) patients, respectively. At 1-year after PVI, 3504 (76.2%) patients were on anticoagulation, and 792 (17.2%) had recurrence of AF. Anticoagulation was continued in over half of AF patients without classic CHA2DS2-VASc indication particularly in those with AF recurrence and women, while they were mildly under-prescribed in those with indication, especially for those without AF recurrence and men. In a large real world cohort of patients after PVI, anticoagulation prescription is not solely depending on the CHA2DS2-VASc score and sex, but also heart rhythm status and other clinical or imaging factors.

Prevalence of ATTR-CA and high-risk features to guide testing in patients referred for TAVR.

PURPOSE: Transthyretin cardiac amyloidosis (ATTR-CA) is thought to be prevalent in patients with severe aortic stenosis (AS) who are referred for transcatheter aortic valve replacement (TAVR). However, prior studies were published when TAVR was only offered to elderly, inoperable, and high-risk patients. The aim of this study was to reevaluate the prevalence of ATTR-CA in a contemporary TAVR population and identify high-risk features to guide referral for technetium-99 pyrophosphate scan (99mTc-PyP scan) screening. METHODS: Patients seen in a multidisciplinary TAVR clinic for severe AS 70 years and older were referred for a 99mTc-PyP scan to evaluate for ATTR-CA. The primary outcome was the percent with a positive scan. The discriminatory ability of high-risk features was assessed to develop a more judicious screening system. RESULTS: Over the study period, 380 patients underwent screening, and 20 patients (5.3%) had a positive scan, with 17 patients having confirmed ATTR-CA, 1 patient deferring confirmatory testing (combined 4.7%), 1 having light chain amyloidosis, and 1 negative on biopsy. Compared to other patient and echocardiographic measures, elevated NT-pro BNP (> 1000 ng/L) was the best discriminator on who should be referred for 99mTc-PyP scan screening, with a sensitivity of 90% and a negative predictive value of 99%. CONCLUSION: The prevalence of ATTR-CA may be lower in a contemporary TAVR population due to its expanded indication for low-risk patients. NT-pro BNP is a simple test that can improve screening yield and more judiciously guide screening for ATTR-CA in this at-risk population. Comparison of the original versus the proposed algorithm.

Coronary vasculopathy due to moyamoya disease.

Moyamoya disease is a rare disorder associated with progressive intracranial arterial stenosis with fragile, small collateralization that gives an angiographic appearance of a puff of smoker or, in Japanese, "moya-moya". We report a case of coronary artery ostial occlusive disease as an extracranial manifestation of Moyamoya. In the case, we demonstrate that thigh risk features of cardiac positron emission tomography (PET) that ultimately lead to the diagnosis of coronary artery occlusion.

Left ventricular assist device infection on 18F-flourodeoxyglucose positron emission tomography.

The rising prevalence of heart failure with limited transplant availability has resulted in increased use of continuous left ventricular assist device (LVAD) support. LVAD driveline remains exposed to environment which predisposes it to high rates of infection. We describe a case of a persistent driveline infection in a patient for which 18F-FDG PET/CT was utilized to diagnose deep-seated infection.

Utility of nuclear cardiovascular imaging in the cardiac intensive care unit.

The contemporary Cardiac Intensive Care Unit (CICU) has evolved into a complex unit that admits a heterogeneous mix of patients with a wide range of acute cardiovascular diseases often complicated by multi-organ failure. Although electrocardiography (ECG) and echocardiography are well-established as first-line diagnostic modalities for assessing patients in the CICU, nuclear cardiology imaging has emerged as a useful adjunctive diagnostic modality. The versatility, safety and accuracy of nuclear imaging (e.g., perfusion, metabolism, inflammation) for the assessment of patient with coronary artery disease, ventricular arrhythmias, infiltrative cardiomyopathies, infective endocarditis and inflammatory aortopathies has been proven useful and now often incorporated into the best practices for the management of critically ill cardiac patients. Thus, clinicians must familiarize themselves with the value and current and future applications of nuclear imaging in the management of the cardiac patient in the CICU.

Utility of positron emission tomography myocardial perfusion imaging for identifying ischemia and guiding treatment in patients with anomalous coronary arteries.

BACKGROUND: The assessment of anomalous coronary arteries (AAOCA) remains controversial without an optimal stress modality for ischemia. We evaluated the value of PET-CT myocardial perfusion imaging in these patients and subsequent management. METHODS AND RESULTS: AAOCA patients (n = 82) undergoing PET-CT from 2015 to 2021 were retrospectively chart reviewed. Multivariable analyses performed to assess relevant clinical and imaging factors associated with ischemia on PET and AAOCA surgery. Key characteristics include mean age 45 ± 20 years, 30 (37%) female, 45 (55%) with chest pain, 19 (23%) anomalous left main coronary artery, 58 (71%) anomalous right coronary artery, 26 (32%) with objective ischemia on PET-CT, and 37 (45%) who underwent AAOCA surgery. Adverse outcomes over mean follow-up of 2.2 ± 1.8 years included one death and two myocardial infarctions. Anomalous left main was independently associated with ischemia on PET-CT, odds ratio (95% confidence intervals) 4.15 (1.31-13.1), P = .006. Chest pain and ischemia on PET-CT were independently associated with and provided incremental prognostic value for surgery, odds ratio 9.73 (2.78-34.0), P < .001 and 6.79 (1.99-23.2), P = .002, respectively. CONCLUSION: Ischemia on PET-CT occurred in a third of our cohort, identifying patients who may benefit from surgery. Larger studies are needed to evaluate the interplay between AAOCA, ischemia by PET and surgery.

Optimal left ventricular ejection fraction in risk stratification of patients with cardiac sarcoidosis.

AIMS: Identifying patients with cardiac sarcoidosis (CS) who are at an increased risk of sudden cardiac death (SCD) poses a clinical challenge. We sought to identify the optimal cutoff for left ventricular ejection fraction (LVEF) in predicting ventricular arrhythmia (VA) and all-cause mortality and to identify clinical and imaging risk factors in patients with known CS. METHODS AND RESULTS: This retrospective cohort included 273 patients with well-established CS. The primary endpoint was a composite of VA and all-cause mortality. A modified receiver operating curve analysis was utilized to identify the optimal cutoff for LVEF in predicting the primary composite endpoint. Cox proportional hazard regression analysis was used to identify independent risk factors of the outcomes. At median follow-up of 7.9 years, the rate of the primary endpoint was 38% (83 VAs and 32 all-cause deaths). The 5-year overall survival rate was 97%. The optimal cutoff LVEF for the primary composite endpoint was 42% in the entire cohort and in subjects without a history of VA. Younger age, history of VA, lower LVEF, and any presence of scar by cardiac magnetic resonance (CMR) imaging and/or positron emission tomography (PET) were found to be independent risk factors for the primary endpoint and for VA, whereas lower LVEF, baseline NT-proBNP, and any presence of scar were independent risk factor of all-cause mortality. CONCLUSION: Among patients with CS, a mild reduction in LVEF of 42% was identified as the optimal cutoff for predicting VA and all-cause mortality. Prior VA and scar by CMR or PET are strong risk factors for future VA and all-cause mortality.

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines.

AIM: This clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients. METHODS: A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing randomized and nonrandomized trials, observational studies, registries, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered. Structure: Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. This guideline presents an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated, and shared decision-making with patients is recommended.

2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain: Executive Summary: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines.

AIM: This executive summary of the clinical practice guideline for the evaluation and diagnosis of chest pain provides recommendations and algorithms for clinicians to assess and diagnose chest pain in adult patients. METHODS: A comprehensive literature search was conducted from November 11, 2017, to May 1, 2020, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Collaboration, Agency for Healthcare Research and Quality reports, and other relevant databases. Additional relevant studies, published through April 2021, were also considered. Structure: Chest pain is a frequent cause for emergency department visits in the United States. The "2021 AHA/ACC/ASE/CHEST/SAEM/SCCT/SCMR Guideline for the Evaluation and Diagnosis of Chest Pain" provides recommendations based on contemporary evidence on the assessment and evaluation of chest pain. These guidelines present an evidence-based approach to risk stratification and the diagnostic workup for the evaluation of chest pain. Cost-value considerations in diagnostic testing have been incorporated and shared decision-making with patients is recommended.

Comparison of anticoagulation with left atrial appendage closure after atrial fibrillation ablation: Rationale and design of the OPTION randomized trial.

BACKGROUND: For patients with symptomatic atrial fibrillation (AF), physicians typically offer AF ablation for symptom relief; however, patients often anticipate/expect a life free from anticoagulation. This belief puts patients at increased risk of stroke due to the potential for asymptomatic AF postablation if anticoagulation is ceased contrary to clinical guidelines. Although the WATCHMAN device has been FDA-approved to decrease the risk of thromboembolism from the left atrial appendage (LAA) in patients with an appropriate rationale to avoid oral anticoagulation, it has not been well-studied following AF ablation. Additionally, there are limited data comparing the WATCHMAN device to direct oral anticoagulants. The OPTION study will investigate whether LAA closure with the WATCHMAN FLX device is a reasonable alternative to oral anticoagulation following percutaneous catheter ablation for nonvalvular AF. TRIAL DESIGN: OPTION is a multinational, multicenter, prospective randomized clinical trial. Patients with a CHA2DS2-VASc of ≥2 in men or ≥3 in women and who underwent a AF catheter ablation procedure between 90 and 180 days prior to randomization (sequential) or are planning to have catheter ablation within 10 days of randomization (concomitant) will be randomized in a 1:1 allocation of WATCHMAN FLX vs control. Control patients will start or continue market-approved oral anticoagulation for the duration of the trial. A total of 1600 patients were randomized from 130 global investigational sites. Follow-up for both device and control patients will occur at 3, 12, 24, and 36 months. The primary effectiveness noninferiority endpoint is stroke (ischemic or hemorrhagic), all-cause death, or systemic embolism at 36 months. The primary safety superiority endpoint is nonprocedural bleeding through 36 months (International Society on Thrombosis and Haemostasis [ISTH] major bleeding or clinically relevant nonmajor bleeding). The secondary noninferiority endpoint is ISTH major bleeding through 36 months (including procedural bleeding). CONCLUSIONS: This trial will assess the safety and efficacy of WATCHMAN FLX in a postablation contemporary clinical AF patient population at risk of stroke.

The Association of Cardiac Biomarkers, the Intensity of Tc99 Pyrophosphate Uptake, and Survival in Patients Evaluated for Transthyretin Cardiac Amyloidosis in the Early Therapeutics Era.

BACKGROUND: Transthyretin amyloid cardiomyopathy (ATTR-CM) is an increasingly recognized cause of heart failure. Given the expansion of noninvasive diagnosis with 99mTc-pyrophosphate (99mTc-PYP) scanning, and clinical use of the transthyretin stabilizer, tafamidis, we sought to examine the interplay of planar imaging heart-to-contralateral lung (H/CL) ratio, cardiac biomarkers, and survival probability in a contemporary cohort of patients referred for noninvasive evaluation of ATTR-CM. METHODS: This single-center retrospective cohort study included 351 consecutive patients who underwent a standardized imaging protocol with 99mTc-PYP scanning for the evaluation of ATTR-CM from January 1, 2018, to January 1, 2020. After the exclusion of light chain amyloidosis, patients were characterized as scan consistent with ATTR (+ATTR-CM) or scan not consistent with ATTR (-ATTR-CM) using current guidelines. Linear regression was used to examine the relationship between biomarkers and H/CL and univariate Cox proportional hazards models were used to assess the probability of transplant-free survival. RESULTS: We included 318 patients in the analysis (n = 86 patients +ATTR-CM; n = 232 patients -ATTR-CM). The median follow-up time was 20.1 months. During the study period, 67% of +ATTR-CM patients received tafamidis (median treatment duration, 17 months). The median H/CL ratio was 1.58 (interquartile range, 1.40-1.75). An H/CL ratio of more than 1.6 or less than 1.6 did not seem to have an impact on survival probability in +ATTR-CM patients (P = .30; hazard ratio, 0.65; 95% confidence interval, 0.31-1.41). Cardiac biomarkers were poorly correlated with H/CL (troponin T, R2 = 0.024; N-terminal pro-B-type natriuretic peptide, R2 =0.023). The Gillmore staging system predicted survival probability in +ATTR-CM as well as in the entire cohort referred for scanning. There was a trend toward longer survival among those who were -ATTR-CM compared with +ATTR-CM (P = .051; hazard ratio, 0.64; 95% confidence interval, 0.40-1.00). CONCLUSIONS: At a large referral center, the intensity of 99mTc-PYP uptake (H/CL ratio) has neither correlation with cardiac biomarker concentrations nor prognostic usefulness in an analysis of intermediate term outcomes in the early therapeutics era. The H/CL ratio has diagnostic value, but offers little prognostic value in patients with ATTR-CM. Established staging schema were predictive of survival in this contemporary cohort, re-emphasizing the importance of cardiac biomarkers and renal function in assessing disease severity and prognosis.

Surgical versus medical management of infective endocarditis after TAVR.

We assessed the incidence of aortic valve surgery intervention in the treatment of infective endocarditis (IE) after transcatheter aortic valve replacement (TAVR) and compared the characteristics and outcomes of surgical intervention versus medical management alone in this cohort using a nationwide data set. We identified all the hospitalizations in patients undergoing TAVR who developed IE within 1-year (i.e., early IE) of the procedure from 2014 to 2017 using the Nationwide Readmission Database (NRD). The primary outcomes of the study were in-hospital mortality. A total of 906 hospitalizations were identified for IE amongst the TAVR patients from 2014 to 2017 of which 20 (2.21%) underwent aortic valve surgery during the hospitalization. Patients undergoing surgery were younger, more likely to have Staphylococcus aureus endocarditis, cardiogenic shock, and acute kidney injury (AKI) during the hospitalization. There were no significant differences in in-hospital mortality (9.9% vs. 12.4%, p = 0.824; adjusted odds ratio (aOR): 0.26 (0.01-1.58), p = 0.223) and 30-day readmissions. However, the length of stay and hospitalization costs were higher in surgical intervention group. The important predictors of in-hospital mortality in TAVR-related IE patients were dialysis during IE hospitalization, AKI, cardiogenic shock, Staphylococcus aureus endocarditis, stroke, and female sex. The utilization of surgical management for IE post-TAVR during the index hospitalization is low, and there is no significant mortality benefit with surgical intervention as compared with the medical management.

Dobutamine stress PET/CT for assessment of hemodynamic significance of coronary myocardial bridges.

Myocardial bridges are common and often benign, but can cause hemodynamically significant obstruction of blood flow with stress. Dobutamine stress positron emission tomography/computed tomography (PET/CT) is a powerful tool for non-invasively assessing for ischemia. We present a case of using dobutamine stress PET/CT to determine the significance of a myocardial bridge.

Initial experience with regadenoson stress positron emission tomography in patients with left bundle branch block: Low prevalence of septal defects and high accuracy for obstructive coronary artery disease.

BACKGROUND: Assessing for coronary artery disease (CAD) in patients with left bundle branch block (LBBB) is difficult with noninvasive cardiac imaging. Few studies report the prevalence of LBBB associated septal-apical perfusion defects using regadenoson stress on Positron Electron Tomography (PET) imaging. METHODS AND RESULTS: We identified 101 consecutive patients with baseline LBBB, and without known CAD, who underwent rest-stress regadenoson PET. Investigators have the ability to prospectively identify studies, whose quality is limited by LBBB artifact. With the infusion of regadenoson, resting to peak stress heart rate rose from a median of 78 to 93 BPM. Despite this, LBBB perfusion artifacts were not identified in any studies. 10 individuals had both regadenoson SPECT and PET within 1 year. 3 of the 10 SPECT studies had LBBB artifacts, all of which were not seen on subsequent PET. 21 patients with PET had subsequent coronary angiography. Of these, 9 PETs were without significant inducible ischemia, and angiogram was without flow-limiting disease. 3 PETs identified inducible ischemia, but did not have flow-limiting disease on angiogram. 9 PETs identified inducible ischemia and had flow-limiting disease on angiogram. CONCLUSIONS: In patients with LBBB undergoing regadenoson PET stress imaging, artifactual septal perfusion defects are rare.

Novel dietary protocol prior to 18F-fluorodeoxyglucose positron emission tomography to evaluate for cardiac sarcoidosis.

The diagnosis of cardiac sarcoidosis (CS) is challenging. Recently, guidelines incorporated cardiac positron emission tomography (PET) with 18F-Fluorodeoxyglucose (F18-FDG) as a non-invasive diagnostic modality for the detection and follow-up of CS. However, this technique is dependent of patient dietary preparation to suppress physiological myocardial F18-FDG uptake. We present a case of possible CS which highlights a novel preparation protocol that facilitated appropriate myocardial suppression.

Initial experience regarding the safety and yield of rest-stress myocardial perfusion imaging in emergency department patients with mildly abnormal high-sensitivity cardiac troponins.

BACKGROUND: With high-sensitivity troponin testing, approximately a third of patients presenting to emergency departments (EDs) with suspected acute coronary syndromes will have mildly abnormal values. However, data regarding rest-stress myocardial perfusion imaging (MPI) in these patients are limited. We hypothesize that stress testing is safe and that the yield for detecting myocardial ischemia is associated with risk stratification by the HEART score. METHODS AND RESULTS: We conducted a retrospective cohort study of consecutive patients referred for rest-stress MPI with mildly abnormal high-sensitivity troponin T (hs-cTn) values. Outcomes were adverse events related to stress MPI, defined as myocardial infarction or ventricular tachyarrhythmia, and the presence of ischemia, defined as a reversible perfusion defect. Among 213 patients, the median age was 67, most were male (61.5%, n = 131), and prior CAD was common (53.5%, n = 114). Myocardial ischemia was present in 13.6% (n = 29), and there were no adverse events attributable to stress MPI. A higher HEART score was associated with myocardial ischemia (Odds Ratio [OR] 1.50, 95% Confidence Interval [CI] 1.08 to 2.08, P = .002). CONCLUSION: Rest-stress MPI appears safe in patients with mildly abnormal hs-cTn values, and the yield for detecting ischemia is associated with the HEART score, though further validation studies are needed.

Incorporating coronary calcification by computed tomography into CHA2DS2-VASc score: impact on cardiovascular outcomes in patients with atrial fibrillation.

AIMS: CHA2DS2-VASc score is widely utilized for risk stratification and guiding anticoagulation in patients with atrial fibrillation (AF). Cardiac computed tomography (CCT) routinely performed for pulmonary vein isolation (PVI) can also identify coronary artery calcifications (CAC). We evaluated the frequency and outcomes of incorporating CAC into the CHA2DS2-VASc score in AF patients undergoing PVI. METHODS AND RESULTS: Consecutive patients in a prospective PVI registry during 2014-18 having CCT within 1 year of PVI were studied. Reclassification of CHA2DS2-VASc score and associations between CAC as a binary variable detected on CCT with clinical characteristics, stroke as primary endpoint, death, myocardial infarction, and major adverse cardiovascular events (MACE) were analysed. Amongst 3604 AF patients, 2238 (62.1%) had CAC detected on CCT and was associated with most traditional cardiovascular risk factors. Coronary artery calcification was independently associated with all pre-specified endpoints adjusting for clinical parameters in multivariable analysis. Adjusting for CHA2DS2-VASc score, CAC was associated with stroke (hazards ratio 3.64, 95% confidence interval 1.25-10.6, P = 0.018), death (2.26, 1.29-3.98, P = 0.006), and MACE (2.08, 1.36-3.16, P = 0.001) during 2.8 ± 1.6-year follow-up. Incorporating CAC as a vascular disease parameter of CHA2DS2-VASc score, anticoagulation decision-making would be revised in 723 (20.1%) patients, including an additional 488 (13.5%) patients where anticoagulation would be now indicated. CONCLUSION: Coronary artery calcification is prevalent in AF patients undergoing PVI and independently associated stroke, death and MACE even when adjusted for traditional CHA2DS2-VASc score. Adding CAC as vascular component to the CHA2DS2-VASc score requires further research as it potentially modified the anticoagulation management in 20% of our AF cohort.

Attenuated heart rate recovery is associated with higher arrhythmia recurrence and mortality following atrial fibrillation ablation.

AIMS: Heart rate recovery (HRR), the decrease in heart rate occurring immediately after exercise, is caused by the increase in vagal activity and sympathetic withdrawal occurring after exercise and is a powerful predictor of cardiovascular events and mortality. The extent to which it impacts outcomes of atrial fibrillation (AF) ablation has not previously been studied. The aim of this study is to investigate the association between attenuated HRR and outcomes following AF ablation. METHODS AND RESULTS: We studied 475 patients who underwent EST within 12 months of AF ablation. Patients were categorized into normal (>12 b.p.m.) and attenuated (≤12 b.p.m.) HRR groups. Our main outcomes of interest included arrhythmia recurrence and all-cause mortality. During a mean follow-up of 33 months, 43% of our study population experienced arrhythmia recurrence, 74% of those with an attenuated HRR, and 30% of those with a normal HRR (P < 0.0001). Death occurred in 9% of patients in the attenuated HRR group compared to 4% in the normal HRR cohort (P = 0.001). On multivariable models adjusting for cardiorespiratory fitness (CRF), medication use, left atrial size, ejection fraction, and renal function, attenuated HRR was predictive of increased arrhythmia recurrence (hazard ratio 2.54, 95% confidence interval 1.86-3.47, P < 0.0001). CONCLUSION: Heart rate recovery provides additional valuable prognostic information beyond CRF. An impaired HRR is associated with significantly higher rates of arrhythmia recurrence and death following AF ablation.