TENUOUS LINK BETWEEN ISCHEMIC THRESHOLD AND BOTH AMBULATORY ISCHEMIA AND SYMPTOM STATUS OVER TIME IN STABLE ANGINA - A 5-YEAR FOLLOW-UP-STUDY

This study evaluates changes in ischaemic threshold over a 5-year peri od in patients with stable angina pectoris, who did not suffer any int ervening cardiac event. Changes in ischaemic threshold are related to alterations in symptomatic status and ambulatory ischaemia. Over long- term follow-up, there is a significant fall in ischaemic threshold in such patients (mean heart rate at onset of ischaemia fell from 104 +/- 17.8 to 97 +/- 17.4 bpm: P < 0.001), but this is not matched by a wor sening of either symptoms or ischaemia during daily life. In the 68% o f patients that had a reduction in ischaemic threshold of greater than or equal to 5 bpm, 68% had either definite reduction or no change in symptoms and 84% had either reduction, abolition or no change in trans ient ischaemic activity. The dissociation between ischaemic threshold, ambulatory ischaemia and symptoms has implications for the long-term monitoring and management of the patient with stable angina.