Comparison between cryoballoon ablation and radiofrequency catheter ablation for atrial fibrillation in patients on hemodialysis.

BACKGROUND: Difficulties are often encountered while controlling atrial fibrillation (AF), especially in hemodialysis (HD) patients. Previous data revealed that cryoballoon ablation (CBA) for treating paroxysmal atrial fibrillation (PAF) was not inferior to radiofrequency ablation (RFA); however, HD patients were excluded in this prior trial. Thus, the efficacy of CBA for HD patients is still unknown. METHODS: This retrospective study analyzed HD patients who underwent catheter ablation (CA) for AF from August 2011 to June 2019. Patients who received CBA (CBA group) and those who received RFA (RFA group) were compared. The primary endpoint was defined as freedom from a composite outcome (a documented recurrence of any atrial tachyarrhythmia or a prescription of antiarrhythmic drugs) at one year after CA. RESULTS: The RFA and CBA groups were composed of 21 and 23 patients, respectively. Freedom from a composite outcome was 58.4% in the RFA group and 68.2% in the CBA group (Log-rank: p = 0.571). CONCLUSION: Our results suggest that patients on HD with AF who were treated with CBA tended to have better outcomes than patients treated with RFA. Therefore, CBA could be a suitable ablation method for HD patients.

Product of heart rate and first heart sound amplitude as an index of myocardial metabolic stress during graded exercise.

BACKGROUND: The double product (DP) breakpoint of heart rate (HR) and systolic blood pressure has been identified as coincident with anaerobic threshold (AT), but there are no simple methods for measuring cardiac metabolic stress (CMS) during an exercise test. It was hypothesized that the DP of HR and the amplitude of the first heart sound (AHS1) (DP-AHS1) would reflect CMS, and thus, the breakpoint in the DP-AHS1 (DPBP-AHS1) could be an alternative method for determining AT. METHODS AND RESULTS: Subjects (age range, 18-73 years) were recruited to perform a graded exercise test on a cycle ergometer with continuous monitoring of DP-AHS1, with left ventricular pressure (LVP; experiment 1, Ex1), plasma catecholamine and blood lactate (experiment 2, Ex2) and gas exchange (experiment 3, Ex3). Ex1: in all subjects there was a strong correlation between AHS1 and LVdP/dtmax (r=0.94-0.98), and between the DP-AHS1 and the triple product of HR, LVdP/dtmax, and max LVP (r=0.98-0.99). Ex2: DP-AHS1 was strongly correlated with adrenaline (r=0.97-1.00) and lactate (r=0.96-1.00) levels in all subjects. Ex3: there was a strong correlation between DPBP-AHS1, AT and maximum oxygen consumption. CONCLUSIONS: The present simple measure of DP-AHS1 can reflect plasma adrenaline and lactate levels during graded exercise testing. Further, DPBP-AHS1 is a surrogate marker of AT and a good index of functional aerobic capacity.

Discordance between fractional flow reserve and instantaneous wave-free ratio in patients with severe aortic stenosis: A retrospective cohort study.

BACKGROUND: Discordance between fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) occurs in approximately 20 % of cases. However, no studies have reported the discordance in patients with severe aortic stenosis (AS). We aimed to evaluate the diagnostic discordance between FFR and iFR in patients with severe AS. METHODS: We examined 140 consecutive patients with severe AS (164 intermediate coronary artery stenosis vessels). FFR and iFR were calculated in four quadrants based on threshold FFR and iFR values of ≤0.8 and ≤0.89, respectively (Group 1: iFR >0.89, FFR >0.80; Group 2: iFR ≤0.89, FFR >0.80; Group 3: iFR >0.89, FFR ≤0.80; and Group 4: iFR ≤0.89, FFR ≤0.80). Concordant groups were Groups 1 and 4, and discordant groups were Groups 2 and 3. Positive and negative discordant groups were Groups 3 and 2, respectively. RESULTS: The median (Q1, Q3) FFR and iFR were 0.84 (0.76, 0.88) and 0.85 (0.76, 0.91), respectively. Discordance was observed in 48 vessels (29.3 %). In the discordant group, negative discordance (Group 2: iFR ≤0.89 and FFR >0.80) was predominant (45 cases, 93.6 %). Multivariate analysis showed that the left anterior descending artery [odds ratio (OR), 3.88; 95 % confidence interval (CI): 1.54-9.79, p = 0.004] and peak velocity ≥5.0 m/s (OR, 3.21; 95%CI: 1.36-7.57, p = 0.008) were independently associated with negative discordance (FFR >0.8 and iFR ≤0.89). CONCLUSIONS: In patients with severe AS, discordance between FFR and iFR was predominantly negative and observed in 29.3 % of vessels. The left anterior descending artery and peak velocity ≥5.0 m/s were independently associated with negative discordance.

Coronary Access After TAVR With a Cylindrical-Shaped Valve: Learning From LOTUS.

BACKGROUND/PURPOSE: Data on the feasibility of coronary access (CA) through above or outside of the cylindrical shaped-transcatheter heart valve (THV) are very limited. The aims of the present study were to assess the feasibility of CA after transcatheter aortic valve replacement (TAVR) with the LOTUS using multi detector computed tomography (MDCT) and the reliability of algorithm detecting unfavorable CA. METHODS/MATERIALS: Post-TAVR MDCT of 41 patients with 82 coronary arteries were evaluated. The relationship and distance between the THV flame and sinotubular junction (STJ) and coronary ostia were assessed. Unfavorable CA was defined as the valve-to-STJ distance < 2-mm or the valve-to-coronary ostia distance < 2-mm if the THV flame was above STJ or coronary ostia. RESULTS: MDCT-identified unfavorable CA was observed in 29.3% for the left coronary artery and 41.5% for the right coronary artery. In total, 53.7% of patients had at least one unfavorable CA and 14.6% of those had unfavorable CA for both left and right coronary artery. While patients underwent coronary angiography after TAVR, the success rates of selective coronary cannulation were significantly lower in patients with MDCT-identified unfavorable CA in comparison to those with favorable CA for left (20.0% vs. 100%, P = 0.002) and right coronary artery (0% vs. 100%, P < 0.001). CONCLUSIONS: Future CA through above or outside of a cylindrical shaped THV may be challenging with a significant probability. Our algorithm identifying unfavorable CA using post-MDCT seems to be useful for estimating the risk of unsuccessful selective cannulation.

Comparison of risk factors for acute worsening renal function in heart failure patients with and without preserved ejection fraction.

OBJECTIVE: We compared the risk factors for acute worsening renal function (AWRF) in patients with acute decompensated heart failure with preserved ejection fraction (HFpEF) versus those with reduced ejection fraction (HFrEF). METHODS: We retrospectively studied 181 consecutive patients. AWRF was defined as a rise in serum creatinine of ≥0.3 mg/dL from admission to day 3. Potential risk factors of AWRF were identified in univariate analyses; then logistic regression analysis with backward stepwise selection was performed. RESULTS: In the present study of limited sample size, 46% had HFpEF (EF≥50%) and 54% had HFrEF (EF<50%). In the HFpEF group, history of hypertension (odds ratio [OR] 32.46, 95% CI 2.39-440.12, P=0.009), the increased serum potassium value at admission (OR 4.61, 95% CI 1.14-18.73, P=0.032), and the pretreatment with calcium channel blocker (OR 8.52, 95% CI 1.21-60.09, P=0.032) were independent risk factors (defined as P<0.05 and OR>1.01) for AWRF. In contrast, diastolic blood pressure at admission (OR 1.07, 95% CI 1.02-1.13, P=0.004) was the sole independent risk factor for AWRF in the HFrEF group. CONCLUSIONS: Hypertension was associated with AWRF in both HFpEF and HFrEF patients. A history of hypertension was more important than elevated blood pressure at admission as a risk factor for AWRF in HFpEF, whereas the reverse was observed for HFrEF. Among antihypertensive drugs, pretreatment with calcium channel blocker was an independent risk factor for AWRF in HFpEF, but not in HFrEF.