The potential of dynamic 99mTc-sestamibi cadmium zinc telluride-single-photon emission computed tomography camera assessing myocardial flow reserve in patients with heart failure with preserved ejection fraction.

Aims: Coronary microvascular dysfunction (CMD) is related to the pathophysiology, mortality, and morbidity of heart failure with preserved ejection fraction (HFpEF). A novel single-photon emission computed tomography (SPECT) camera with cadmium zinc telluride (CZT) detectors allows for the quantification of absolute myocardial blood flow and myocardial flow reserve (MFR) in patients with coronary artery disease. However, the potential of CZT-SPECT assessing for CMD has never been evaluated in patients with HFpEF. Methods and results: The clinical records of 127 consecutive patients who underwent dynamic CZT-SPECT were retrospectively reviewed. Rest and stress scanning were started simultaneously with 3 and 9 MBq/kg of 99mTc-sestamibi administration, respectively. Dynamic CZT-SPECT imaging data were analysed using a net-retention model with commercially available software. Transthoracic echocardiography was performed in all patients. The MFR value was significantly lower in the HFpEF group (mean ± SEM = 2.00 ± 0.097) than that in the non-HFpEF group (mean ± SEM = 2.74 ± 0.14, P = 0.0004). A receiver operating characteristic analysis indicated that if a cut-off value of 2.525 was applied, MFR could efficiently distinguish HFpEF from non-HFpEF. Heart failure with preserved ejection fraction had a consistently low MFR, regardless of the diastolic dysfunction score. Heart failure with preserved ejection fraction patients with MFR values lower than 2.075 had a significantly higher incidence of heart failure exacerbation. Conclusion: Myocardial flow reserve assessed by CZT-SPECT was significantly reduced in patients with HFpEF. A lower MFR was associated with a higher hospitalization rate in these patients. Myocardial flow reserve assessed by CZT-SPECT has the potential to predict future adverse events and stratify the severity of disease in patients with HFpEF.

Correction to: Differences in prothrombotic response between the uninterrupted and interrupted apixaban therapies in patients undergoing cryoballoon ablation for paroxysmal atrial fibrillation: a randomized controlled study.

In the original publication of the article, the table 2 was published incorrectly.

Differences in prothrombotic response between the uninterrupted and interrupted apixaban therapies in patients undergoing cryoballoon ablation for paroxysmal atrial fibrillation: a randomized controlled study.

Periprocedural bleeding and thromboembolic events are worrisome complications of catheter ablation for atrial fibrillation (AF). Periprocedural anticoagulation management could decrease the risk of these complications. However, evaluation of the complications from pulmonary vein isolation using cryoballoon related to different anticoagulation strategies is limited. Therefore, we aimed to compare prothrombotic responses as assessed on the basis of D-dimer levels between the uninterrupted and interrupted apixaban therapies during cryoballoon ablation. Ninety-seven consecutive patients with paroxysmal AF scheduled to undergo cryoballoon ablation were randomly assigned in a 1:2 ratio to uninterrupted apixaban therapy (Group 1, n = 32) or interrupted apixaban therapy (Group 2, n = 65). D-Dimer levels were measured immediately before the ablation, at the end of the ablation, and 24 and 48 h after the procedure. No statistical difference was observed in the baseline characteristics between the two groups. The rates of hemorrhagic complications were similar in both groups (major bleeding: 3.1 vs. 1.5%; p = 0.61, and minor bleeding: 3.1 vs. 4.6%; p = 0.73, respectively). No thromboembolic events occurred in either group. However, D-dimer levels 48 h after the ablation increased more markedly following the procedure in Group 2 than in Group 1 (from 0.58 ± 0.16 to 1.01 ± 0.42 µg/mL vs. 0.58 ± 0.20 to 0.82 ± 0.25 µg/mL; p = 0.01). In conclusion, uninterrupted apixaban therapy during the periprocedural period of cryoballoon ablation for AF did not increase the risk of bleeding in this study and might reduce the periprocedural risk of subclinical hypercoagulable state.

Head-to-head comparison of acute and chronic pulmonary vein stenosis for cryoballoon versus radiofrequency ablation.

BACKGROUND: Cryoballoon (CB) applications to pulmonary veins (PVs) can cause stenosis just as radiofrequency (RF) energy deliveries. The goal of the present study was to clarify whether or not there was any difference in the extent of acute or chronic PV narrowing after PV isolation between the two different energy sources. METHODS: Consecutive patients with paroxysmal atrial fibrillation who were scheduled to undergo a PV isolation were randomized 1:1 to receive CB or RF ablation. The endpoints were any acute PV narrowing assessed with the use of intracardiac ultrasound during the procedure and PV stenosis measured with cardiac computed tomography at the 3-month follow-up. RESULTS: An acute reduction in the luminal area of the left superior PV (mean ± standard deviation, -6.8 ± 8.7 vs -19.9 ± 14.7%; P < 0.001) and left inferior PV (-5.1 ± 20.2 vs -15.3 ± 11.6%; P = 0.03) was significantly smaller in the CB arm (N = 25) than the RF arm (N = 25). There was no difference in the extent of PV stenosis 3 months after the ablation between the arms (0-25% stenosis, 90% vs 88%, 25-50% stenosis, 10% vs 12%, >50% stenosis, both 0%; P = 0.82). A greater acute PV narrowing was likely to lead to chronic stenosis in the RF arm (P = 0.004). CONCLUSIONS: CB ablation may reduce the acute narrowing of the left-sided PVs as compared to RF ablation.

Cardiac resynchronization therapy for patients with cardiac sarcoidosis.

Aims: Sarcoidosis with cardiac involvement is a rare pathological condition, and therefore cardiac resynchronization therapy (CRT) for patients with cardiac sarcoidosis is even further rare. We aimed to clarify the clinical features of patients with cardiac sarcoidosis who received CRT. Methods and results: We retrospectively reviewed the clinical data on CRT at three cardiovascular centres to detect cardiac sarcoidosis patients. We identified 18 (8.9%) patients with cardiac sarcoidosis who met the inclusion criteria out of 202 with systolic heart failure who received CRT based on the guidelines. The majority of the patients were female [15 (83.3%)] and underwent an upgrade from a pacemaker or implantable cardioverter defibrillator [13 (72.2%)]. We found 1 (5.6%) cardiovascular death during the follow-up period (mean ± SD, 4.7 ± 3.0 years). Seven (38.9%) patients had a composite outcome of cardiovascular death or hospitalization from worsening heart failure within 5 years after the CRT. Twelve (66.7%) patients had a history of sustained ventricular arrhythmias or those occurring after the CRT. Among the overall patients, no significant improvement was found in either the end-systolic volume or left ventricular ejection fraction (LVEF) 6 months after the CRT. A worsening LVEF was, however, more likely to be seen in 5 (27.8%) patients with ventricular arrhythmias after the CRT than in those without (P = 0.04). An improved clinical composite score was seen in 10 (55.6%) patients. Conclusions: Cardiac sarcoidosis patients receiving CRT may have poor LV reverse remodelling and a high incidence of ventricular arrhythmias.

Don't expect left ventricular reverse remodeling after cardiac resynchronization therapy in patients with systolic heart failure and atrioventricular block: A multicenter study.

BACKGROUND: The BLOCK HF trial showed that heart failure patients with atrioventricular block (AVB) and left ventricular systolic dysfunction (LVSD) are considered good candidates for cardiac resynchronization therapy (CRT), even though they have a narrow QRS duration. We aimed to compare the clinical response to CRT between patients with AVB combined with LVSD and patients with pre-existing CRT indications. METHODS: We compared the clinical data on CRT across the following 3 groups in 3 cardiovascular centers; heart failure patients with an LV ejection fraction (LVEF) of ≤35% who had a QRS duration of ≥120ms (standard indication, n=125), those needing an upgrade to CRT (upgrade, n=49), and patients with an LVEF of ≤50% who had advanced AVB (AVB with LVSD, n=27). RESULTS: The prevalence of left bundle branch block differed significantly across the groups (87.2%, 98.0% and 40.7%; P<0.001). No inter-group difference was found in the percentage of patients in whom clinical composite score (CCS) assessed 6months after the CRT was improved (60.8%, 57.1% and 70.4%; P=0.67). Whereas, even among the patients with an improved CCS, a significantly smaller LV end-systolic volume reduction after the CRT was seen in the ABV with LVSD group (-35.3±34.7, -21.4±28.5 and -5.2±23.9%; P=0.001). The incidence of cardiovascular death or hospitalization from heart failure within 5years occurred with a similar frequency (44%, 55.1% and 44.4%; P=0.9). CONCLUSIONS: As compared to patients with preexisting CRT indications, CRT may be similarly effective for patients with AVB and LVSD, however, LV reverse remodeling may be uncommon among them.

Who is the operator, that is the question: a multicentre study of catheter ablation of atrial fibrillation.

AIMS: A worldwide survey reported that the success rate of atrial fibrillation (AF) ablation was higher in high-volume centers compared with low-volume centers. We tested whether the procedure volume of each operator was associated with the outcome of AF ablation in high-volume centres. METHODS AND RESULTS: We studied 471 patients with paroxysmal AF who underwent pulmonary vein (PV) isolation for the first time in three cardiovascular centers where the annual AF ablation volume was >100 procedures. We classified a total of 10 primary operators according to their operation volume on the basis of ACC/AHA/ACP CLINICAL COMPETENCE STATEMENT; high-volume operator (≥50 cases/year, N = 3) or low-volume operator (<50 cases/year, N = 7). The patients included were dichotomized according to the annual operation volume of their attending physician. The endpoints were the freedom from AF recurrence 1 year after the ablation, major complications including thromboembolisms, massive bleeding or death, and the procedural duration. RESULTS: A complete isolation of the four PVs was achieved in 99.1%. The freedom from AF recurrence was more common in patients treated by high-volume operators than those treated by low-volume operators (165/216 [76.4%] vs. 160/255 [62.8%]; P = 0.001). A high-volume operator was the only independent predictor of the freedom from AF recurrence (hazard ratio 1.73, 95% confidence interval 1.23-2.48; P = 0.002). The patients treated by high-volume operators were less likely to have major complications (1.4% vs. 7.8%; P = 0.001), and had a shorter procedural duration (139.9 ± 25.3 vs. 149.3 ± 27.1 min; P = 0.03). CONCLUSIONS: Operator proficiency may predict the outcome after AF ablation even in high-volume centres.