Clinical Corner with Dr. Keith Dawkins: IVL-Induced Ventricular Capture

Perspective on IVL-Induced Ventricular Capture from Keith D. Dawkins, M.D., Chief Medical Officer, Shockwave Medical, Inc.:

Late last week, one of our customers in the UK reported in the European Heart Journal what appears to be the first reported case of ventricular fibrillation (VF) associated with IVL. We appreciate that this case report was published in order for physicians to be informed of this rare event.

VF associated with IVL use is rare based on our clinical and commercial experience: this is the first report we are aware of in over 25K coronary IVL cases performed to date.

The report describes in detail how, in an off-label case, a severely calcified in-stent restenosis of the right coronary artery (RCA), IVL spikes fell on a T-wave, which then in-turn seems to have induced VF.

For background, IVL produces a low amount of mechanical energy, which is capable of inducing premature ventricular beats in primarily bradycardic patients, known as ‘IVL-induced ventricular capture,’ which was described well in the EuroIntervention publication from Wilson et al who documented its first report. It is important to understand that no electrical current leaves the IVL catheter. Rather, a small amount of mechanical energy is transferred to the vessel wall when sonic pressure waves are created that have been shown to create a stretch activated response in the myocardium.

Last month, the Disrupt CAD III clinical trial investigators published in JACC the first prospective analysis on this topic as part of the 431-patient U.S. IDE study, which showed IVL-induced capture was common but benign, with the authors noting, “Decreased systolic blood pressure during the IVL procedure was more frequent in patients with IVL-induced capture compared to those without (40.5% vs. 24.5%; p = 0.0007). However, the magnitude of the drop in systolic blood pressure was similar between the 2 groups (18.9 vs. 23.5 mmHg systolic; p = 0.07). IVL-induced capture did not result in sustained ventricular arrhythmias during or immediately after the IVL procedure in any patient and was not associated with adverse events.”

While acknowledging that VF can occur in any case, diagnostic or interventional, a recently published report showed that the risk of VT or VF is 0.8% in diagnostic angiography, 1.1% for stable PCI and as much as 4.3% for primary PCI in AMI. In these cases, VF may also be caused by ischemic events, for example prolonged balloon inflations, not related to IVL.

VF is typically reversible with cardioversion in the cath lab, as was the case in this published report.

We understand IVL-induced ventricular capture, and while we have not heard of any other VF reports, we will continue to monitor this topic and encourage our customers to continue to report complaints to our quality team at complaint@shockwavemedical.com.

Important Safety Information - Coronary IVL

Caution: In the United States, Shockwave C2 Coronary IVL catheters are investigational devices, limited by United States law to investigational use in the DISRUPT CAD III Study. Shockwave C2 Coronary IVL catheters are commercially available in certain countries outside the U.S. Please contact your local Shockwave representative for specific country availability. The Shockwave C2 Coronary IVL catheters are indicated for lithotripsy-enhanced, low-pressure balloon dilatation of calcified, stenotic de novo coronary arteries prior to stenting. For the full IFU containing important safety information please visit: https://shockwavemedical.com/clinicians/international/coronary/shockwave-c2/