PVC Variability and Impact on Meeting Expert Consensus Cutoffs of ≥ 10 000 PVCs/Day and ≥ 15% PVCs

BACKGROUND: Frequent PVCs have been associated with a reversible cardiomyopathy. Cutoffs of ≥ 10 000 PVCs/day and ≥ 15% PVCs have been suggested by the 2014 EHRA/HRS/APHRS and 2017 AHA/ACC/HRS Expert Consensus guidelines, respectively, for PVC suppression. OBJECTIVE: To investigate the impact of PVC variability on meeting guideline-suggested PVC thresholds. METHODS: Six hundred and six patients with 14-day ZIO monitor data sets with ≥ 10 000 PVCs on at least 1 day were identified (2014 guidelines cohort). Of these patients, 325 had at least 1 day of ≥ 15% PVCs (2017 guidelines cohort). Analysis was performed on these cohorts. RESULTS: Within the 2014 guidelines cohort, mean daily PVC burden was 12 188 ± 8300 [range 0-64 188]. Intra-patient daily PVCs were highly variable (median 3.6-fold change between max and min PVC days (Q1/3: 2.22/10.15) with instances of > 10 000-fold change observed. 54.3% and 19.5% of patients had days with < 5000 and < 1000 PVCs, respectively. Even patients with days of 0 PVCs (0.5%) were observed. Seventy-two hours of monitoring detected 69% of patients with ≥ 10 000 PVCs/24 h with an additional 2%-4% of patients crossing the threshold each additional day. A bimodal distribution of the number of days meeting PVC thresholds/corresponding PVC counts was observed, suggesting a previously unidentified pattern of distinct populations-"low frequency/low PVC" (≤ 3/14 above-threshold days/mean 12 342 PVCs those days) versus "high frequency/high PVC" (14/14 above-threshold days/mean 24 580 PVCs those days). The 2017 guidelines cohort demonstrated similar findings. CONCLUSION: Daily PVC burdens vary greatly. More sensitive detection of guideline-suggested cut-offs requires prolonged monitoring. Novel potential PVC patterns may allow for better identification of candidates for PVC suppression.