University of Oulu

Ikäheimo, T. M., Länsitie, M., Valtonen, R., Hintsala, H. E., Ryti, N., Perkiömäki, J., … Jaakkola, J. J. K. (2019). Good safety practice in a randomized controlled trial (CadColdEx) involving increased cardiac workload in patients with coronary artery disease. BMC Cardiovascular Disorders, 19(1).

Good safety practice in a randomized controlled trial (CadColdEx) involving increased cardiac workload in patients with coronary artery disease

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Author: Ikäheimo, Tiina M.1,2; Länsitie, Miia1,2; Valtonen, Rasmus1,2;
Organizations: 1Center for Environmental and Respiratory Health Research, University of Oulu, P.O. Box 5000, FI-90014 Oulu, Finland
2Medical Research Center Oulu, Oulu University Hospital and University of Oulu, FI-90014 Oulu, Finland
3Research Unit of Internal Medicine, University of Oulu, FI-90014 Oulu, Finland
4The Finnish Defence Forces, Aeromedical Centre, FI-00290 Helsinki, Finland
5Cardiovascular Research Group, Division of Cardiology, Oulu University Hospital, University of Oulu, Oulu, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 0.6 MB)
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Language: English
Published: Springer Nature, 2019
Publish Date: 2019-06-12


Background: Methodological information acknowledging safety of cardiac patients in controlled medical experiments are lacking. The descriptive report presents one good practice for considering safety in a randomized controlled study involving augmented cardiovascular strain among persons with coronary artery disease (CAD).

Methods: The patients were pre-selected by a cardiologist according to strictly defined selection criteria. Further confirmation of eligibility included screening of health. In addition, assessments of physical capacity by a graded bicycle ergometer test were implemented and safety monitored by an exercise physiologist and medical doctor. In this context, an emergency simulation was also carried out. A total of 18 CAD patients each underwent four different experimental interventions where either temperature (+ 22 °C and − 15 °C) and the level of exercise (rest and brisk walking) were employed for 30 min in random order (72 experiments). Baseline (20 min) and follow-up (60 min) measurements were conducted resting at + 22 °C. ECG, and brachial blood pressure were measured and perceived exertion and symptoms of chest pain inquired throughout the experiments. An emergency nurse was responsible for the health monitoring and at least two persons followed the patient throughout the experiment. A medical doctor was available on call for consultation. The termination criteria followed the generally accepted international guidelines for exercise testing and were planned prior to the experiments.

Results: The exercise test simulation revealed risks requiring changes in the study design and emergency response. The cardiovascular responses of the controlled trials were related to irregular HR, ST-depression or post-exercise hypotension. These were expected and the majority could be dealt on site by the research personnel and on call consultation. Only one patient was encouraged to seek for external health care consultation.

Conclusions: Appropriate prospective design is a key to safe implementation of controlled studies involving cardiac patients and stimulation of cardiovascular function. This includes careful selection of participants, sufficient and knowledgeable staff, as well as identifying possible emergency situations and the required responses.

Trial registration: ClinicalTrials ID: NCT02855905.

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Series: BMC cardiovascular disorders
ISSN: 1471-2261
ISSN-E: 1471-2261
ISSN-L: 1471-2261
Volume: 19
Issue: 1
Article number: 69
DOI: 10.1186/s12872-019-1051-1
Type of Publication: A1 Journal article – refereed
Field of Science: 3121 General medicine, internal medicine and other clinical medicine
Funding: The study was funded by the Finnish Ministry of Education and Culture and Yrjö Jahnsson Foundation.
Copyright information: © The Author(s). 2019 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (, which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated.