Risk Stratification for Pericardial Effusion After Leadless Pacemaker Implantation ― Multicenter Study ―

Q: What are the key findings of this study?

Preoperative risk stratification using the original risk score and a modified score stratified postoperative pericardial effusion after Micra implantation.

Q: What is the clinical evidence from this study?

Study design: Cohort. Population: Bradycardia treated with Micra leadless pacemaker implantation (n=443). Intervention: High preoperative Risk Score (RS ≥2) for pericardial effusion vs. Low preoperative Risk Score (RS ≤0). Primary outcome: Occurrence of postoperative pericardial effusion (PPE) assessed immediately and at 24-48 hours post-implantation (p=0.041).

Q: What does this research mean for the field?

Preoperative risk stratification using an existing risk score and a modified version successfully stratifies the incidence of postoperative pericardial effusion after Micra leadless pacemaker implantation in Japanese patients. Novelty: ClaimNovelty.INCREMENTAL. Consensus alignment: ConsensusAlignment.NEUTRAL.

Yuya Komai; Hitoshi Minamiguchi; Masayuki Ishimura; Yuichiro Sakamoto; Masahiro Nakano; Takatsugu Kajiyama; Miyo Nakano; Toshinori Chiba; Satoko Ryuzaki; Yukiko Takanashi; Yusei Nishikawa; Takashi Kanda; Mikiko Matsumura; Naoki Mori; Yuma Hamanaka; Takashige Sakio; Yuki Shibuya; Daisuke Yoshimoto; Yuko Uemura; Shoko Narumi; Yoshio Kobayashi; Yusuke Kondo

doi:10.1253/circj.cj-25-1061

Key result

Risk stratification scores predict postoperative pericardial effusion risk after Micra leadless pacemaker implantation.

P=0.041
n=443

Why the study?

Postoperative pericardial effusion is a known complication after leadless pacemaker implantation, and the utility of risk stratification using a risk score in Japanese patients was evaluated.

Does preoperative risk stratification using the original Risk Score (RS) and a modified Risk Score (mRS) effectively predict postoperative pericardial effusion in Japanese patients undergoing Micra leadless pacemaker implantation?

Key Points

To assess the utility of an established risk score for predicting postoperative pericardial effusion after leadless pacemaker implantation and optimize it for Japanese patients.
Retrospectively evaluated 443 patients who underwent Micra leadless pacemaker implantation across 4 institutions between August 2017 and August 2024.
Stratified patients into low-risk (score ≤0), intermediate-risk (score 1), and high-risk (score ≥2) groups using both the original risk score and a newly developed modified risk score.
Postoperative pericardial effusion occurred in 9.0% (20/221), 11.7% (9/77), and 17.9% (26/145) of patients in the low-, intermediate-, and high-risk groups under the original risk score (P=0.041).
Multivariable analysis showed chronic obstructive pulmonary disease significantly increased effusion risk (OR 3.32, 95% CI 1.28–8.63, P=0.014), whereas prior cardiac surgery was protective (OR 0.094, 95% CI 0.012–0.72, P=0.023).
The modified risk score demonstrated improved discrimination, with effusion rates of 8.8% (27/306) in low-, 16.5% (14/85) in intermediate-, and 26.9% (14/52) in high-risk categories (P<0.001).

Study Design

Type

Cohort (n=443)

Multicenter

Yes

Structured PICO

Does preoperative risk stratification using the original Risk Score (RS) and a modified Risk Score (mRS) effectively predict postoperative pericardial effusion in Japanese patients undergoing Micra leadless pacemaker implantation?

P

Population

443 elderly Japanese patients (mean age 82.9 years, 39.3% female) undergoing Micra leadless pacemaker implantation across 4 institutions, assessed for postoperative pericardial effusion within 24-48 hours.

E

Exposure

Preoperative risk stratification using the original Piccini Risk Score (RS: low ≤0, intermediate 1, high ≥2) and a post-hoc modified Risk Score (mRS: excluding age, sex, and hemodialysis; maintaining COPD as +2; changing prior cardiac surgery from -1 to -2; keeping BMI <20 kg/m2, CHF, and pulmonary hypertension as +1, and AF and CAD as -1).

C

Comparator

Comparison across risk categories (low risk vs. intermediate risk vs. high risk) and discriminative performance comparison between the original RS and the modified RS (mRS).

O

Outcome

Occurrence of postoperative pericardial effusion (PPE), defined as newly detected pericardial effusion on transthoracic echocardiography or computed tomography immediately after implantation and 24-48 hours later, or progression of pre-existing effusion by ≥10 mm in diastole or causing hemodynamic compromise.safety

Main Result

Absolute Event Rate: 17.9% vs 9%

p-value: p=0.041

Limitations

Retrospective and observational design with potential selection and reporting biases
Modest sample size and limited number of events, particularly for symptomatic pericardial effusion (n=5)
Diagnostic and management approaches for pericardial effusion were not fully standardized across institutions
Anatomical and procedural parameters such as implantation depth, septal positioning, and operator experience were not quantitatively evaluated
Postoperative pericardial effusion occurring beyond 48 hours after the procedure was not evaluated
Exclusively included Japanese patients, limiting generalizability to other ethnic groups
Retrospective and observational design introducing potential selection and reporting biases
Modest sample size and limited number of events, particularly for symptomatic pericardial effusion
Diagnostic and management approaches for pericardial effusion were not fully standardized among participating institutions
Anatomical and procedural parameters (implantation depth, septal positioning, operator experience) and anatomic difficulty were not quantitatively evaluated
PPE occurring beyond 48 hours after the procedure was not evaluated
Study exclusively included Japanese patients, limiting generalizability to other ethnic groups and healthcare systems

Ask about this paper

Answers are grounded in this paper and cite their sources.

Implication

In Japanese patients undergoing Micra leadless pacemaker implantation, COPD significantly increases and prior cardiac surgery significantly reduces postoperative pericardial effusion risk, and a modified risk score omitting age, sex, and hemodialysis improves risk stratification over the original score.

Abstract

BACKGROUND: Postoperative pericardial effusion (PPE) is a known complication associated with the use of leadless pacemakers (LPMs). The risk score (RS) is a useful tool for risk stratification. This study evaluated the utility of risk stratification using the RS in Japanese patients who received the Micra LPM. METHODS AND RESULTS: We retrospectively enrolled 443 patients who received Micra LPMs that were implanted at 4 institutions between August 2017 and August 2024. Patients were risk stratified using the RS into 3 groups: low risk (score ≤0), intermediate risk (score 1), and high risk (score ≥2). PPEs were observed in 9.0% (20/221), 11.7% (9/77) and 17.9% (26/145) of patients in the low-, intermediate-, and high-risk groups, respectively (P=0.041). In multivariable analysis, chronic obstructive pulmonary disease was a significant risk factor (P=0.014) for PPE, whereas prior cardiac surgery significantly reduced the risk of PPE (P=0.023). Older age, being female, and hemodialysis were not identified as risk factors. Subsequently, we modified the RS (mRS). Using the mRS, PPEs were observed in 8.8% (27/306), 16.5% (14/85), and 26.9% (14/52) of patients in the low-, intermediate-, and high-risk groups, respectively (P<0.001). CONCLUSIONS: The original RS is useful for PPE risk stratification after Micra LPM implantation. However, the mRS provides better risk discrimination and may therefore be a more suitable tool for use in the Japanese population.

Discussion

No takes yet. Share an insight, caveat, or question.

Cite This Study

Komai et al. (2026) conducted a cohort in Bradycardia treated with Micra leadless pacemaker implantation (n=443). High preoperative Risk Score (RS ≥2) for pericardial effusion vs. Low preoperative Risk Score (RS ≤0) was evaluated on Occurrence of postoperative pericardial effusion (PPE) assessed immediately and at 24-48 hours post-implantation (p=0.041). Preoperative risk stratification using the original risk score and a modified score stratified postoperative pericardial effusion after Micra implantation.

synapsesocial.com/papers/6ac1abf9cc6172083c928b58 https://doi.org/10.1253/circj.cj-25-1061

View Full Paper

Ask AI

Bookmark

Share

Risk Stratification for Pericardial Effusion After Leadless Pacemaker Implantation ― Multicenter Study ―

Key Points

Study Design

Structured PICO

Main Result

Limitations

Ask about this paper

Implication

Abstract

Discussion

Cite This Study

Risk Stratification for Pericardial Effusion After Leadless Pacemaker Implantation ― Multicenter Study ―

Key Points

Study Design

Structured PICO

Main Result

Limitations

Ask about this paper

Implication

Abstract

Discussion

Cite This Study

Keep reading

Keep reading