Acute and Chronic Pain

Pain resulting from coronary heart diseases and their associated treatment is underestimated and often neglected. More research is needed to get a better understanding of the nature and impact of the pain, to improve analgesic practices, and to develop preventive strategies.

The research program we recently developed at the Montreal Heart Institute (MHI) is aimed at studying the characteristics, impact, and treatment of pain associated with coronary heart diseases, and especially after surgical interventions. Last year, we did a cross-sectional study involving 736 patients who underwent coronary artery bypass grafting (CABG) and/or valve replacement (VR) at the MHI between 1999 and 2002 (results in the process of being published). Response rate was 79%.  Our prevalence results showed that more than one patient in five (23%) reported chronic pain one year or more after their surgery. Pain was most often present in the thorax area, and was different from pain felt prior to surgery (e.g., anginal pain).  A substantial number of patients reported that their pain was severe enough to interfere with their daily life activities.  Interestingly enough, we observed some relationship between the patients' analgesic needs during their hospitalization and the development of chronic postoperative pain.

We are currently conducting a study whose objective is to identify some sociodemographic, medical/surgical and/or psychological factors which may put cardiac surgery patients more at risk of developing chronic postoperative pain.  A prospective follow up design is used to study a cohort of 1400 patients scheduled to undergo CABG and/or VR. The total follow up period is  24 months.  This study will allow us to document, at various times prior to and after surgery, different aspects of the pain including its intensity, time course, and  impact in terms of interference with everyday activities, psychological well-being and health related quality of life.  Various pre- and post-operative risk factors of chronic pain will be examined including pain intensity in the first few days after surgery and analgesic treatment during this period.

These studies and others which are in the process of being developed with regards to pain treatment and prevention, are part of a larger research program aimed at improving the management of acute and chronic pain associated with coronary heart diseases and their treatment.