Abstract 11044: Elevated Heart Rate Two Weeks after Onset, Despite Successful Reperfusion Therapy, Indicates Poor Prognosis in Patients with a First ST-Elevation Acute Myocardial Infarction
Background The role of resting heart rate (HR) during chronic phase of ST elevation acute myocardial infarction (STEMI) is not yet understood. We used echocardiography to assess the role of resting HR in STEMI.
Method A total of 237 consecutive STEMI patients (age = 63 ± 12 years, male = 170) underwent echocardiography and had their HR checked 2 weeks after onset. We examined the tissue Doppler imaging, then calculated the early transmitral flow velocity (E) divided by the early diastolic velocity of the mitral valve annulus (e’) - a ratio that strongly correlates with mean left ventricular (LV) filling pressure both at medial and lateral side then averaged (mean-E/e’). All had undergone successful emergency PCI within 12 hours of onset. Infarct size was assessed by area under the curve (AUC)-creatine phosphokinase (CPK) or ejection fraction (EF) 2 weeks after onset. They were followed for 51 ± 11 months. Primary endpoint was cardiac death or readmission due to heart failure. The index values used were typically the worst (highest) quartile values.
Results All patients had similar backgrounds and were divided into four groups based on HR (a) HR (/min) <59, (b)59 - 66, (c)67 - 75, (d)75<. No significant differences were found in the frequency of administering β-blockers , age , sex, AUC-CPK or culprit vessels among four groups (p=ns). Group (d) had highest mean-E/e’ among four groups: E/e’ (a)11.0±0.6, (b)10.6±0.6, (c) 9.9±0.6, (d)12.0±0.6 (p=0.12). During the follow-up periods, primary endpoint occurred in 35 patients (8 cardiac deaths, 27 readmissions for heart failure). Table shows Cox proportional hazard models for prognosticator assessment, multivariate analysis showed HR >75 to be the independent predictor for the primary endpoint as well as E/e’ >14.2 and age >73.
Conclusion The presence of an elevated resting heart rate 2 weeks after onset, despite successful reperfusion therapy and optical medical treatments, may suggest a poor prognosis for a first STEMI.
- © 2011 by American Heart Association, Inc.