Abstract P316: Lower Mortality From Ischemic Heart Disease Associated With Attenuation of Autonomic Dysfunction is Related to Reduction of Sensitivity to Pain at the Chest Bone

Abstract

Introduction: Autonomic nervous system dysfunction (ANSD) is associated with negative prognosis of ischemic heart disease (IHD) and has been found also to be related to elevated measures of sensitivity to pain from pressure (PPS) at the sternum. Previously, we found that non-pharmacological intervention by peripheral sensory nerve stimulation, monitored by repeated home-based PPS measurements, consistently was associated with lowered PPS measures. Compared to the general Danish population, the intervention reduced the all-cause mortality in two prospective observations, one of 103 patients with IHD followed for 3 years, and one of 73 patients with stroke followed for 4.5 years. Here, we test if we can reproduce lower all-cause mortality associated with lowered PPS measures in a randomized controlled trial (RCT). Methods: Of 361 consecutively followed patients with stable IHD, 65% had elevated PPS, suggestive of ANSD. Of these, 213 participated in a randomized controlled trial (RCT) with active (n=106) or passive intervention (n=107). We compared the 5-year all-cause mortality of both groups with two corresponding subsections of approximately 35.000 members of the general population of Denmark, matching patients for gender, age, and observation period with data from Statistics Denmark, and we compared the 5-year mortality of the two RCT groups. In separate analyses, we pooled mortality data from the active group of the RCT with data from two observational studies. We registered the pooled active intervention mortality of 1.168 person-years, compared to approximately 40 million person-years of the pooled general population. Results: We observed fewer than three deaths in the active RCT group (exact number and 95% CI not available according to GDRP rules), compared to eight deaths of passive RCT group members (P=0.035). Based on the predicted mortality from the general population of eight deaths in both groups, the result is consistent with significantly reduced mortality of recipients of active intervention (P=0.011). The separate analyses of pooled data from three consecutive studies demonstrated a mean reduction of the 4.2-year all-cause mortality of 50% (P<0.00005). Conclusions: The predicted attenuation of ANSD associated with lowering of elevated PPS matched the lower all-cause mortality of patients with IHD.