Ralota KK, Tuncer D, Htun NM, Samuel R, Gupta V, Lew R, Layland J. Fixed vs weight-based heparin dosing in stable patients undergoing diagnostic coronary physiology studies. World J Cardiol 2026; 18(1): 112321 [DOI: 10.4330/wjc.v18.i1.112321]
Corresponding Author of This Article
Jamie Layland, MD, PhD, FRACP, MRCP, Professor, Senior Researcher, Department of Cardiology, Peninsula Health and Department of Medicine, Peninsula Clinical School, Monash University, 2 Hastings Road, Frankston 3199, Victoria, Australia. jlayland@phcn.vic.gov.au
Research Domain of This Article
Cardiac & Cardiovascular Systems
Article-Type of This Article
Retrospective Cohort Study
Open-Access Policy of This Article
This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
World J Cardiol. Jan 26, 2026; 18(1): 112321 Published online Jan 26, 2026. doi: 10.4330/wjc.v18.i1.112321
Fixed vs weight-based heparin dosing in stable patients undergoing diagnostic coronary physiology studies
Kristoffer Ken Ralota, Deniz Tuncer, Nay Min Htun, Rohit Samuel, Vivek Gupta, Robert Lew, Jamie Layland
Kristoffer Ken Ralota, Deniz Tuncer, Nay Min Htun, Rohit Samuel, Vivek Gupta, Robert Lew, Jamie Layland, Department of Cardiology, Peninsula Health, Frankston 3199, Victoria, Australia
Jamie Layland, Department of Medicine, Peninsula Clinical School, Monash University, Frankston 3199, Victoria, Australia
Author contributions: Ralota KK and Tuncer D contributed to data collection and draft the manuscript; Ralota KK checked the data, its content, flow, and narrative, enacted the necessary revisions of the manuscript, preparation and submission of the current version of the manuscript; Layland J is the senior researcher who conceptualized the study, helped in vetting of related literature, and supervised the entire process. Htun NM, Samuel R, Gupta V, Lew R, and Layland J contributed to review the manuscript. All authors have read and approved the final manuscript.
Institutional review board statement: The study was approved by our institutional Human Research Ethics Committee with approval number LNR/107040/PH-2024.
Informed consent statement: Patients were not required to give informed consent to the study because the analysis used anonymous clinical data that were obtained after each patient agreed to treatment by written consent.
Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article.
STROBE statement: The authors have read the STROBE Statement-checklist of items, and the manuscript was prepared and revised according to the STROBE Statement-checklist of items.
Open Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Jamie Layland, MD, PhD, FRACP, MRCP, Professor, Senior Researcher, Department of Cardiology, Peninsula Health and Department of Medicine, Peninsula Clinical School, Monash University, 2 Hastings Road, Frankston 3199, Victoria, Australia. jlayland@phcn.vic.gov.au
Received: July 24, 2025 Revised: September 24, 2025 Accepted: December 8, 2025 Published online: January 26, 2026 Processing time: 176 Days and 0.4 Hours
Abstract
BACKGROUND
Unfractionated heparin (UFH) is routinely used during coronary angiography, but the optimal dosing strategy for diagnostic coronary physiology procedures such as fractional flow reserve or microvascular assessment in stable patients remains unclear. While weight-based dosing is standard in percutaneous coronary intervention, a fixed-dose approach may simplify workflow.
AIM
To compare bleeding and thromboembolic outcomes between fixed-dose and weight-based UFH during diagnostic coronary physiology procedures without percutaneous coronary intervention.
METHODS
We conducted a retrospective single-center study of 128 patients undergoing fractional flow reserve or microvascular testing from January 2021 to February 2024. Patients received either fixed-dose (5000 IU) or weight-based (70-100 IU/kg) UFH. The primary outcome was a composite of thromboembolic complications: Radial artery occlusion, stroke, or periprocedural myocardial infarction. Secondary outcomes included bleeding (Bleeding Academic Research Consortium criteria), association with patient characteristics, access site, and length of stay.
RESULTS
Of 128 patients, 78 received fixed-dose and 50 received weight-based UFH. No thromboembolic events occurred in either group. Bleeding (all Bleeding Academic Research Consortium 1-2) occurred in 15% overall, with no significant difference between groups (15% vs 12%, P = 0.47). No significant association between bleeding and patient age, sex, weight, body mass index, access site, antiplatelet, or anticoagulant use. Median hospital stay was 1 day in both groups.
CONCLUSION
In this exploratory study, a fixed 5000 IU UFH regimen appeared to be a safe and practical alternative to weight-based dosing in diagnostic coronary physiology procedures. Larger prospective studies are warranted to confirm these findings.
Core Tip: This study explores the safety and efficacy of fixed-dose vs weight-based unfractionated heparin dosing during diagnostic coronary physiology procedures. Among 128 patients, fixed-dose 5000 IU unfractionated heparin was associated with similarly low rates of bleeding and no thrombotic events compared to weight-based dosing. These findings suggest that a fixed-dose approach may be a safe and practical alternative in low-risk, physiology-only settings. The results may inform future research and support consideration of simplified anticoagulation strategies in stable patients undergoing diagnostic coronary physiology assessments.
