Influence of age on pain perception in acute myocardial ischemia: A possible cause for delayed treatment in elderly patients

Background: Elderly patients tend to seek later for medical help during myocardial infarction. This may be caused by impaired pain perception with ageing. The aim of our study was to prospectively evaluate age-dependent differences in pain perception during temporary induced coronary ischemia. Methods: In 102 patients (68 male, age 68 ± 11 years) undergoing percutaneous coronary intervention, ischemia was induced by balloon inflation for up to 120 s. Time to onset of perceived pain, pain characteristics and pain severity (0 = no pain, 100 = worst pain possible) was registered. This was repeated twice to evaluate ischemic preconditioning. A 12 lead ECG-tracing was simultaneously recorded. Patients were divided by their median age into 2 groups with comparable demographics: ≤ 69 years (group 1) and > 69 years (group 2). Results: Group 1 patients demonstrated earlier onset of pain (most apparent during the second inflation: 31 ± 15 s vs. 46 ± 26 s; p < 0.001), and greater pain severity (inflation #1: 64 ± 21 vs. 51 ± 25 [p = 0.017]; #2: 66 ± 23 vs.52 ± 27 [p = 0.008]; #3: 63 ± 23 vs. 54 ± 24 [p = 0.085]). ST-changes did not differ (0.24 ± 0.10 vs. 0.20 ± 0.14, [p = 0.18]; 0.27 ± 0.17 vs. 0.20 ± 0.14, [p = 0.11]; 0.19 ± 0.13 vs. 0.16 ± 0.09; [p = 0.32]). Time from occlusion to onset of ECG changes did not differ between the groups, but increased with repetitive inflations (inflation #1: 29 ± 11 s vs. 29 ± 11 s; #2: 31 ± 14 vs. 33 ± 11; #3: 39 ± 21 vs. 40 ± 15 s [increase p = 0.017; p < 0.001]). Conclusion: These data suggest that the perception of pain from myocardial ischemia in the elderly is significantly less severe and delayed compared to younger patients.