Prognostic Implications of Premature Ventricular Contractions and Non-sustained Ventricular Tachycardia in Light-Chain Cardiac Amyloidosis.

BACKGROUND AND AIMS: Premature ventricular contractions (PVC) and non-sustained ventricular tachycardia (NSVT) are commonly observed in light chain cardiac amyloidosis (AL-CA), but their association with prognosis is still unclear. We aimed to evaluate the prognostic value of PVCs and NSVT in patients with moderate-to-advanced AL-CA.

METHODS: We retrospectively included patients with AL-CA at modified 2004 Mayo stages II-IIIb between February 2014 and December 2020. Twenty-four-hour Holter recordings were assessed on admission. The outcomes included 1) new onset of adverse ventricular arrhythmia (VA) or SCD and 2) cardiac death during follow-up.

RESULTS: Of the 143 patients studied (60.4±11.1 years, male 64.3%), 132 (92.3%) had presence of PVC and 50 (35.0%) had NSVT on Holter. Twelve (8.4%) patients died in hospital and 131 patients were followed up (median 24.4 months), among whom 71 patients had cardiac death, 15 underwent adverse VA/SCD. NSVT [HR: 13.57, 95% CI: 3.06-60.18, p<0.001], log-transformed PVC counts (HR:1.46,95%CI:1.15-1.86, p=0.002) and PVC burden (HR:1.43 95%CI:1.14-1.80, p=0.002) were predictive of new onset of adverse VA/SCD. The highest tertile of PVC counts (HR: 2.33, 95%CI: 1.27-4.28, p=0.006) and PVC burden (HR: 2.58, 95%CI: 1.42-4.69, p=0.002), rather than NSVT (HR:1.16, 95%CI: 0.67-1.98, p=0.603), was associated with cardiac death. Higher PVC counts/burden provided incremental value on modified 2004 Mayo stage in predicting cardiac death, with C index increasing from 0.681 to 0.712 and 0.717, respectively (p values <0.05).

CONCLUSIONS: PVC count, burden and NSVT significantly correlated with adverse VA/SCD during follow-up in patients with AL-CA. Higher PVC counts/burden added incremental value for predicting cardiac death.