Ablation of atrial tachyarrhythmias late after surgical correction of tetralogy of Fallot: long-term follow-up.

BACKGROUND: After the surgical correction of tetralogy of Fallot, surgical scars and natural obstacles form pathways capable of supporting an atrial tachyarrhythmia (AT). Radiofrequency (RF) ablation is effective, although the few studies published on this topic had relatively short follow-up periods. AIM: The aims of the study were to evaluate the acute and long-term effects of RF ablation of AT and examine the charac-teristics of arrhythmia recurrence. METHODS: Tetralogy of Fallot patients (n = 16, age 44.7 ± 10.7 years) referred for ablation of ATs, appearing 25.7 ± 9.6 years after repair, were studied. RESULTS: Twenty-five ATs were ablated, including 16 cavo-tricuspid isthmus atrial flutters (CTI-AFLs) and nine intraatrial reentrant tachycardia (IART). In one patient with paroxysmal atrial fibrillation (PAF), pulmonary vein isolation was also performed. Ten patients had permanent, and six had paroxysmal arrhythmia prior to the first ablation. Four patients had PAF. Regardless of the type of first ablated arrhythmia, all 16 patients required CTI-AFL ablation. The effectiveness of the first RF ablation reached 88%. The acute efficacy of RF ablation was 100% for CTI-AFL and 78% for IART. Long-term follow-up was possible in 15 out of 16 patients (mean follow-up 68.8 ± 36.6 months). Four patients were free of sustained arrhythmia, nine (60%) had AF. After the last RF ablation, an episode suggestive of CTI-AFL/IART was documented only in one patient. CONCLUSIONS: Ablation of CTI-AFL/IART in tetralogy of Fallot patients is safe and effective. AF was observed in most patients during the long-term follow-up. Regardless of the type of the first ablated arrhythmia, all patients required CTI-AFL ablation.

Ablation of Macro-Re-Entrant Atrial Arrhythmia Late after Surgical Aortic Valve Replacement.

BACKGROUND: Re-entrant atrial arrhythmias are common in patients after cardiac surgery. To date, however, no studies have reported the safety and efficacy of radiofrequency (RF) ablation of macro-re-entrant atrial arrhythmias in a unique, homogeneous group of patients after surgical replacement of the aortic valve and single right atriotomy. METHODS: Among over 4,000 RF catheter ablations performed at the authors' center between 2008 and 2014, eight patients (seven males, one female; mean age 55.1 ± 19.9 years) after aortic valve replacement (AVR) and without history of any other cardiosurgical procedures were identified with documented macro-re-entrant atrial arrhythmia. The mechanism of macro-re-entrant arrhythmia was analyzed, as well as the safety and efficacy of RF ablation in a group of patients after AVR and single right atrial free wall atriotomy. RESULTS: The average time from surgery to RF catheter ablation was 11.3 ± 11.3 years (range: 4-35 years). In five patients with permanent arrhythmia, entrainment mapping proved these arrhythmias to be cavotricuspid isthmus- dependent, in three patients with paroxysmal atrial arrhythmia cavotricuspid isthmus-dependent atrial flutter was induced during the electrophysiological study. Intra-atrial re-entrant tachycardia was neither recorded nor induced in any patient. Successful ablation of cavotricuspid isthmus is defined as the termination of arrhythmia, and bidirectional block in cavotricuspid isthmus was achieved in all patients. A long-term follow up, based on a seven-day Holter monitoring, was conducted in all patients, with a mean observation time of 40.1 ± 28.6 months after the procedure. Among the patients, ablated arrhythmia (cavotricuspid isthmusdependent atrial flutter) recurred in one patient, atrial fibrillation occurred in three patients, and an atrial tachycardia in one patient. CONCLUSIONS: In the presented series of patients, cavotricuspid isthmus-dependent atrial flutter was shown to be the mechanism of post-cardiosurgical macro-re-entrant clinical arrhythmia in all subjects. Atrial fibrillation was frequently observed among those patients during follow up.

Old markers, new approach to assessment of risk in heart failure.

BACKGROUND: Heart transplantation (HTx) is still the optimal treatment for refractory heart failure (HF). However, there is great disproportion between the number of donors and potential recipients. Several parameters are used in patient evaluation before HTx, but the qualification process still requires improvement. High-sensitivity C-reactive protein (hsCRP) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) possess high prognostic value for patients with advanced HF. AIM: To assess the prognostic significance of NT-proBNP and hsCRP separately, as well as in combination, in a group of patients with advanced HF, considered for HTx. METHODS: Registry ­ 632 patients referred for HTx in Poland (2003­2007). Following proper treatment correction and routine clinical evaluation (i.e. mean New York Heart Association [NYHA] classification 3.2 ± 0.6, heart rate 77 ± 15 bpm, systolic/diastolic blood pressure [SBP/DBP] 103/67 ± 15/11 mm Hg, left ventricular ejection fraction [LVEF] 22 ± 8%, serum Na+ 136 ± 4 mmol/L, NT-proBNP 3942 ± 5637 pg/mL, hsCRP 9 ± 22 mg/L levels, HFSS according to Aaronson 8 ± 1, etc.) patients were qualified for HTx. Based on ROC analysis (cut-off points for NT-proBNP 2435 pg/mL and hsCRP 2.4 mg/L) subjects were stratified into four subgroups: (1) non-elevated hsCRP (­)/NT-proBNP (­) (n = 179); (2) non-elevated hsCRP (­)/ /elevated NT-proBNP (+) (n = 92); (3) elevated hsCRP (+)/non-elevated NT-proBNP (­) (n = 159); and (4) elevated hsCRP (+)/ /NT-proBNP (+) (n = 202). The end point was defined as death/urgent HTx. The mean follow-up period was 601 days. RESULTS: In univariate regression analysis we confirmed that classical risk factors were independent predictors of end point: NYHA (HR = 2.311; p < 0.0001), heart rate (HR = 1.016; p = 0.0009), SBP (HR = 0.984; p = 0.0111), LVEF (HR = 0.951; p < 0.0001), serum Na+ (HR = 0.901; p < 0.0001), NT-proBNP (HR = 1.004; p = 0.0159), and hsCRP (HR = 1.010; p = 0.0002); HFSS (HR = 0.557; p < 0.0001). Frequency-of-events analysis revealed that patients in the hsCRP (­)/ /NT-proBNP (­) subgroup presented with the best prognosis (13% of patients reached end point) followed by the hsCRP (­)/ /NT-proBNP (+) subgroup, in which 24% of patients reached end point (Kaplan-Meier c2 = 8.5319; p = 0.0035) and the hsCRP (+)/NT-proBNP (+) subgroup (c2 = 42.0413; p < 0.0001), which was associated with the worst prognosis (39% of patients reached end point). CONCLUSIONS: The classical risk factors: NYHA class, heart rate, SBP, LVEF, HFSS, serum Na+, NT-proBNP, and hsCRP concentrations, proved to be valuable in the assessment of risk in advanced HF patients. However, concomitant evaluation of old markers: hsCRP and NT-proBNP, may become a good prognostic tool for identification of highest-risk patients among all referred for HTx. Such a new approach to risk stratification before HTx seems promising but requires further investigation.

Severe chronic heart failure in patients considered for heart transplantation in Poland.

BACKGROUND: Based on the results of clinical trials, the prognosis for patients with severe heart failure (HF) has improved over the last 20 years. However, clinical trials do not reflect 'real life' due to patient selection. Thus, the aim of the POLKARD-HF registry was the analysis of survival of patients with refractory HF referred for orthotopic heart transplantation (OHT). METHODS: Between 1 November 2003 and 31 October 2007, 983 patients with severe HF, referred for OHT in Poland, were included into the registry. All patients underwent routine clinical and hemodynamic evaluation, with NT-proBNP and hsCRP assessment. Death or an emergency OHT were assumed as the endpoints. The average observation period was 601 days. Kaplan-Meier curves with log-rank and univariate together with multifactor Cox regression model the stepwise variable selection method were used to determine the predictive value of analyzed variables. RESULTS: Among the 983 patients, the probability of surviving for one year was approximately 80%, for two years 70%, and for three years 67%. Etiology of the HF did not significantly influence the prognosis. The patients in NYHA class IV had a three-fold higher risk of death or emergency OHT. The univariate/multifactor Cox regression analysis revealed that NYHA IV class (HR 2.578, p < 0.0001), HFSS score (HR 2.572, p < 0.0001) and NT-proBNP plasma level (HR 1.600, p = 0.0200), proved to influence survival without death or emergency OHT. CONCLUSIONS: Despite optimal treatment, the prognosis for patients with refractory HF is still not good. NYHA class IV, NT-proBNP and HFSS score can help define the highest risk group. The results are consistent with the prognosis of patients enrolled into the randomized trials.