Author + information
- Published online March 4, 2019.
- Kalilur Anvardeen, MBBS,
- Rajeev Rao, MD,
- Samir Hazra, MD,
- Karen Hay,
- Hongyan Dai, MD, PhD,
- Nik Stoyanov, MBBS,
- David Birnie, BSc (Hons), MBChB, MD,
- Girish Dwivedi, MD, PhD and
- Kwan Leung Chan, MD∗ ()
- ↵∗University of Ottawa Heart Institute, 40 Ruskin Street, Ottawa, Ontario K1Y 4W7, Canada
Endocardial lead in the right ventricle (RV) is recognized as a cause for tricuspid regurgitation (TR), but the prevalence and significance are not well defined (1). The objectives of the study were to prospectively assess the prevalence of TR in this clinical setting, evaluate the functional significance of TR, and assess the relationship between the development of TR, with the location of the endocardial lead determined by 3-dimensional (3D) echocardiography.
The study was approved by the Research Ethics Board, and all subjects provided written informed consent. We enrolled adult patients scheduled for implantation of permanent pacemaker or implantable cardioverter-defibrillator. Patients with moderate or greater TR, RV dilatation or dysfunction, RV systolic pressure ≥70 mm Hg, or suboptimal echocardiographic images were excluded. The subjects had pre-procedural echocardiograms within 48 h before lead implantation, and follow-up echocardiograms (both 2-dimensional and 3D) at 4 to 6 weeks, 6 months, and 1 year. Left ventricular dimensions and ejection fractions by the biplane Simpson method were obtained. Assessment of the right atrium (RA) and RV included RA area, RA major and minor dimensions, RV fractional area change, tricuspid annular plane systolic excursion, and RV annular systolic velocity. The grading of TR severity was based on existing guidelines. Mild or less TR was categorized into none or trace, mild, and mild-moderate based on the jet areas of <1 cm2, 1 to 3 cm2, and 3 to 5 cm2, respectively. Three-dimensional images of the tricuspid valve were obtained at the first follow-up visit at 4 to 6 weeks, and were analyzed using the multiplanar reconstruction software QLab version 10 (Philips Healthcare, Andover, Massachusetts) to determine the location of the endocardial lead at the tricuspid annulus.
The Student’s t-test was used to compare continuous data in normal distribution which were provided as mean ± SD. Continuous data in skewed distribution were provided as median values and compared through the Mann-Whitney U test. Categorical data were compared using Fisher exact or chi-square test, and a logistic regression model was used to test for interaction. All reported probability values were 2 tailed, and a p value <0.05 was considered statistically significant.
Between February 2013 and June 2015, 153 patients were recruited in the study. Twenty-five patients were subsequently excluded for the following reasons: atrial lead only in 1, endocardial lead not implanted in 2, consent withdrawal in 1, suboptimal study images in 1, deceased in 2, and no follow-up at 12 months in 18. Of the 128 patients who had complete follow-up, the mean age was 66.8 ± 12.4 years, and there were 94 (73%) women. Atrial fibrillation was present in 5 patients and atrial flutter was present in 2 patients. A permanent pacemaker was implanted in 61 patients and implantable cardioverter-defibrillator was implanted in 67 patients.
Before the procedure, mild TR was detected in 38 patients and mild-moderate TR was detected in 4 patients. TR severity increased in 38 patients and decreased in 8 patients. Increase in TR severity was by 1 grade in 32 of 38 (84%) patients. The changes in echocardiographic measurements from baseline to follow-up at 12 months were examined in the 38 patients with increase in TR severity and in the 90 patients with no worsening TR (Table 1). Significant increases in RA and RV dimensions and right ventricular systolic pressure were present only in patients with an increase in TR severity.
In both groups the leads were at or near the commissures in approximately one-half of the patients, with the posteroseptal commissure being the most common location. The endocardial lead was against the leaflet in 17 of 38 (44%) patients with and in 32 of 90 (35%) patients without new or worse TR (p = NS).
It is generally accepted that TR can develop following endocardial lead implantation in the RV, but previous studies were largely retrospective (1). We showed that new or increased TR was common following RV endocardial lead placement at the 12-month follow-up. Although TR was largely mild, it was associated with remodeling of right heart chambers. These findings suggest that mild TR is not benign, consistent with the observation by Nemoto et al. (2), who showed that mild TR was associated with enlarged tricuspid annulus and RA dilatation assessed by 3D computed tomography. Few patients in our study had atrial fibrillation or pulmonary hypertension, which are risk factors for the development of TR (3), underscoring the role of endocardial lead as a cause for TR. A longer-term follow-up is indicated to better assess the impact of TR in this setting.
Please note: Dr. Rao has received speaker honoraria from Novartis, Pfizer/BMS, and AstraZeneca. Dr. Hazra has received unrestricted research grant support from GE Healthcare; and speaker fees and honoraria from Servier Canada and Bayer Pharma. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- 2019 American College of Cardiology Foundation