Atrial Tachyarrhythmias After Cardiac Transplantation

Radiofrequency ablation of supraventricular arrhythmias after orthotopic heart transplantation: Long-term follow-up of a single-center experience

BACKGROUND

Supraventricular arrhythmias (SVAs), commonly managed with radiofrequency ablation (RFA), may occur after orthotopic heart transplantation (OHT).

METHODS

We retrospectively assessed 514 consecutive patients (pts.) undergoing OHT between January 1990 and July 2016 in a single-center. Patients with SVAs managed with RFA were included. Mechanisms of genesis of SVAs, association with surgical techniques and outcomes, were analyzed.

RESULTS

Of 514 pts undergoing OHT, 53% (272 pts.) were managed with bicaval (BC) technique and 47% (242 pts.) with biatrial (BA) technique. Mean follow-up 10 ± 8.4 years. Nine pts. (1.7%) developed SVA requiring RFA. The BC technique was performed in 4 pts., 3 pts. presented cavotricuspid isthmus-dependent atrial flutter (CTI AFL), and 1 pt. double loop AFL. Five pts. were managed with BA technique, 4 pts. presented CTI AFL, and 1 pt. atrial tachycardia (AT). Mean time between OHT and SVA occurrence was 6.6 ± 5.5 years. The procedure was successful in 89% (8 pts.). Arrhythmia recurrence was seen in 3 pts (37%), all with BA technique.

CONCLUSION

Supraventricular arrhythmias in heart transplantation may be associated with the surgical scar. Identifying the mechanism is vital to choose the appropriate treatment with radiofrequency ablation.

Atrial fibrillation following heart transplantation: A systematic review and meta-analysis of observational studies

OBJECTIVE

Previous studies have suggested a high incidence of atrial fibrillation (AF) in heart transplant recipients. However, incidence trends of AF in heart transplant recipients remain unclear. The study's aims were (1) to investigate the pooled incidence/incidence trends of AF following heart transplantation and (2) to assess the mortality risk of heart transplant recipients with AF.

METHODS

A literature search for studies that reported the incidence of AF following heart transplantation was conducted using MEDLINE, EMBASE, and The Cochrane Database from inception through March 2018. Pooled incidence and odds ratios (OR) with 95%CI were calculated using a random-effects model.

RESULTS

Eighteen studies (2 cohorts from clinical trials and 16 cohort studies) with 5393 heart transplant recipients were enrolled. The pooled estimated incidence of AF in heart transplant was 10.1% (95%CI: 7.6%-13.2%). Meta-analysis based on the type of anastomotic technique demonstrated a pooled estimated incidence of AF following heart transplantation of 18.7% (95%CI: 10.3%-31.5%) and 11.1% (95%CI: 6.5%-18.4%) by biatrial and bicaval techniques, respectively. There was a significant association between AF following a heart transplant and increased mortality risk with a pooled OR of 2.86 (95%CI: 2.08-3.93). Meta-regression analyses showed no significant correlations between the year of study and incidence of AF (P = 0.47) or mortality risk of AF after heart transplantation (P = 0.99).

CONCLUSIONS

The overall estimated incidence of AF following heart transplantation is 10.1%. There is a significant association between AF and increased mortality after transplantation. Furthermore, incidence and mortality risk of AF following heart transplant does not seem to decrease over time.