Methodology of DNA extraction and sequencing from living cardiomyocytes collected by catheter in humans

We present here the technical feasibility of percutaneously retrieving cardiomyocytes (CMs) through the lumen of irrigated ablation catheters, with the aim of obtaining DNA of sufficient quality/quantity for allowing DNA amplification, screening, and derived genetic analysis.

Irrigated conventional catheters for ablation were used for creating endocardial right ventricular voltage maps in 38 patients with suspected or proved arrhythmogenic right ventricular cardiomyopathy. Blood material was collected from scar areas by aspiration and filtered, CMs detected by light microscopy were aspirated, centrifugated, and freezed.DNA was extracted, amplified, and sequenced, and variants were compared with variants obtained from leukocyte DNA.

At least 1 CM was obtained in 95% of patients (median 11 CM/patient). After refinements of the technique, a total of 136 samples (22 patients) allowed DNA extraction and amplification, successful in 60% of samples (16 patients). DNA capture sequencing of a panel of cardiomyopathy-associated genes was successfully performed in 14 patients and compared with blood sequencing in 11. After controlled by Sanger, an additional variant, not present in blood, has been confirmed in CM in one patient.

This new mini-invasive technique of sampling allows to perform genetic analysis on CMs. Pending future improvements, this technique could provide new sources of human cells for research and potential mosaicism detection.