Background: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is associated with ventricular arrhythmias (VA) and sudden cardiac death (SCD). A model was recently developed to predict incident sustained VA in patients with ARVC. However, since this outcome may overestimate the risk for SCD, we aimed to specifically predict life-threatening VA (LTVA) as a closer surrogate for SCD. Methods: We assembled a retrospective cohort of definite ARVC cases from 15 centers in North America and Europe. Association of 8 prespecified clinical predictors with LTVA (SCD, aborted SCD, sustained, or implantable cardioverter-defibrillator treated ventricular tachycardia >250 beats per minute) in follow-up was assessed by Cox regression with backward selection. Candidate variables included age, sex, prior sustained VA (≥30s, hemodynamically unstable, or implantable cardioverter-defibrillator treated ventricular tachycardia; or aborted SCD), syncope, 24-hour premature ventricular complexes count, the number of anterior and inferior leads with T-wave inversion, left and right ventricular ejection fraction. The resulting model was internally validated using bootstrapping. Results: A total of 864 patients with definite ARVC (40±16 years; 53% male) were included. Over 5.75 years (interquartile range, 2.77–10.58) of follow-up, 93 (10.8%) patients experienced LTVA including 15 with SCD/aborted SCD (1.7%). Of the 8 prespecified clinical predictors, only 4 (younger age, male sex, premature ventricular complex count, and number of leads with T-wave inversion) were associated with LTVA. Notably, prior sustained VA did not predict subsequent LTVA ( P =0.850). A model including only these 4 predictors had an optimism-corrected C-index of 0.74 (95% CI, 0.69–0.80) and calibration slope of 0.95 (95% CI, 0.94–0.98) indicating minimal over-optimism. Conclusions: LTVA events in patients with ARVC can be predicted by a novel simple prediction model using only 4 clinical predictors. Prior sustained VA and the extent of functional heart disease are not associated with subsequent LTVA events.

To investigate outcome and complications of implantable cardioverter defibrillators (ICDs) in adults with congenital heart disease (CHD) and to identify predictors of (in-) appropriate shocks. Sixty-four CHD patients ≥ 18 years at first ICD implantation [63% tetralogy of Fallot (TOF) and age at implantation 37 ± 13 years] were identified using the Dutch adult CHD registry and a Belgian tertiary care centre database. Median follow-up duration was 3.7 years. Early complications included pocket haematoma (n = 3), lead failure (n = 2), and pneumothorax (n = 2). Late complications occurred in 11 (17%) patients, including lead failure (n = 6) and and electrical storm (n = 3). Overall, 30 device-related re-interventions were performed in 20 patients (31%), including four premature generator changes and seven lead replacements. Half of the patients received one or more shocks, and 46 shocks in 15 patients (23%) were classified as appropriate. One hundred and sixty shocks in 26 patients (41%) were classified as inappropriate. No predictors of (in-)appropriate shocks were identified, except TOF being associated with less appropriate shocks than patients with other CHD (HR 0.29, P = 0.02). The ICD provided effective therapy in a quarter of adults with CHD with low complication rates. The incidence of inappropriate shocks, however, appeared to be excessive and warrants further attention.

Objective  To compare the risks of complications during pregnancy in women with repaired and unrepaired atrial septal defects (ASDs) without associated complex cardiac lesions.Design  A retrospective multicentre study.Setting  Tertiary centres in the Netherlands and Belgium.Population  Women with ASD without associated complex cardiac lesions.Methods  Women were identified using two congenital heart disease registries. One hundred women were identified who had 243 pregnancies, including 49 miscarriages and six terminations of pregnancy. Detailed information on each completed pregnancy (n = 188; unrepaired ASD, n = 133; repaired ASD, n = 55) was obtained using medical records and telephone interviews. In addition, data from the Generation R database (a prospective cohort study; n = 9667) were used to determine the background risk (control group).Main outcome measures  Adjusted odds ratios (AORs) for cardiac, obstetric and neonatal events controlled for multiple pregnancies per woman using general estimating equation analysis.Results  Women with an unrepaired ASD had a higher risk of neonatal events (AOR = 2.99, 95% confidence interval [CI] 1.14–7.89, P = 0.027) than women with a repaired ASD. The risk of cardiac and obstetric complications was comparable between women with unrepaired and repaired ASDs. Compared with the general population, women with an unrepaired ASD had higher risks of pre‐eclampsia (AOR = 3.54, 95% CI 1.26–9.98, P = 0.017), small‐for‐gestational‐age births (AOR = 1.95, 95% CI 1.15–3.30, P = 0.013) and fetal mortality (AOR = 5.55, 95% CI 1.77–17.4, P = 0.003). By contrast, no differences were observed when comparing women with a repaired ASD versus controls.Conclusions  Women with an unrepaired ASD are at increased risk of neonatal events in comparison with women with a repaired ASD. Compared with the general population, women with an unrepaired ASD are at increased risk of pre‐eclampsia, small‐for‐gestational‐age births and fetal mortality.

Introduction: Recently a novel cryoballoon system (POLARx, Boston Scientific) became available for the treatment of atrial fibrillation. This cryoballoon is comparable with Arctic Front Advance Pro (AFA‐Pro, Medtronic), however, it maintains a constant balloon pressure. We compared the procedural efficacy and biophysical characteristics of both systems.Methods: One hundred and ten consecutive patients who underwent first‐time cryoballoon ablation (POLARx: n = 57; AFA‐Pro: n = 53) were included in this prospective cohort study.Results: Acute isolation was achieved in 99.8% of all pulmonary veins (POLARx: 99.5% vs. AFA‐Pro: 100%, p = 1.00). Total procedure time (81 vs. 67 min, p < .001) and balloon in body time (51 vs. 35 min, p < .001) were longer with POLARx. After a learning curve, these times were similar. Cryoablation with POLARx was associated with shorter time to balloon temperature −30°C (27 vs. 31 s, p < .001) and −40°C (32 vs. 54 s, p < .001), lower balloon nadir temperature (−55°C vs. −47°C, p < .001), and longer thawing time till 0°C (16 vs. 9 s, p < .001). There were no differences in time‐to‐isolation (TTI; POLARx: 45 s vs. AFA‐Pro 43 s, p = .441), however, POLARx was associated with a lower balloon temperature at TTI (−46°C vs. −37°C, p < .001). Factors associated with acute isolation differed between groups. The incidence of phrenic nerve palsy was comparable (POLARx: 3.5% vs. AFA‐Pro: 3.7%).Conclusion: The novel cryoballoon is comparable to AFA‐Pro and requires only a short learning curve to get used to the slightly different handling. It was associated with faster cooling rates and lower balloon temperatures but TTI was similar to AFA‐Pro.