Title: Triggered acute risk prevention (TARP II): A study of feasibility in subjects with cardiovascular risk factors

Research team: Professor Geoffrey Tofler, Dr Tom Buckley, Monica Spinaze (RN), Dr Elizabeth Shaw, Dr Michael Ward

Funded since 2008

Overview

The purpose of the research is to investigate whether it is possible to reduce the risk of heart attack by taking medication at the time of potential triggers of (heavy exertion, severe emotional stress, heavy meal and respiratory infection).

We recently confirmed that such an approach was feasible and well tolerated in 20 healthy subjects. However, before large-scale testing and implementation is possible, we need to confirm feasibility in higher risk individuals, and for longer duration.

We are therefore studying this area in 30 higher-risk individuals with cardiovascular risk factors.

This is a leading research group in the field, as indicated by international requests to write summary chapters in books and journals regarding this research area.

Report: current study

The research is proceeding well, with 15 subjects recruited. Initial results are promising.

Background: previous study

Heavy physical exertion, emotional stress, heavy meals and respiratory infection transiently increase the risk of myocardial infarction, sudden death and stroke. However, it remains uncertain how to use this information for disease prevention.

Aims

We determined the feasibility of taking targeted medication for the hazard duration of a triggering activity to reduce risk.

Methods

After a run-in training period over one month, 17 healthy subjects recorded for one month all episodes of physical and emotional stress, heavy meals and respiratory infection. For each episode, they were instructed to take either:

• aspirin 100 mg and propranolol 10 mg (for physical exertion and emotional stress) or
• aspirin 100mg alone (for respiratory infection and heavy meal)

and record their adherence with taking medication.

Subjects performed exertion while wearing a heart rate monitor, once during the run-in period, and once 30 minutes after taking propranolol and aspirin.

Results

Based on the study diary, subjects reliably documented triggers, with 94% adherence. Designated medication was also reliably taken, with 88% adherence.

Propranolol taken prior to exertion resulted in a lower peak heart rate (128+/-38 versus 149+/-21, p<0.01) compared to similar exercise during the run-in period.

Over two-thirds (71%) of subjects considered that it was feasible to continue taking medication in this manner.

Conclusions

The study indicates that potential triggers of acute cardiovascular disease can be reliably identified, and it is feasible and acceptable to take targeted medication at the time of these triggers. These findings encourage further investigation of the potential role of this therapeutic strategy.

Publications

There is no publication from this study to date.

Results from the initial study among healthy subjects:

Shaw, E., Tofler, G., Buckley, T., Bajorek, B., Ward, M. ‘Therapy for triggered acute risk prevention: A study of feasibility.' Heart, Lung and Circulation 18, no. 5 (October 2009): 347-52.