RELEVANCE OF HEART-RATE AS A PROGNOSTIC FACTOR IN PATIENTS WITH ACUTEMYOCARDIAL-INFARCTION - INSIGHTS FROM THE GISSI-2 STUDY

Aims It is as yet undefined whether simple indexes of autonomic balanc e such as heart rate (HR) may play a role in risk stratification in pa tients with acute myocardial infarction (MT). The aim of this study wa s to quantify the prognostic significance of HR from the surface ECG o btained both at entry and at discharge, in a large population of patie nts all treated with fibrinolysis during the acute phase and having co nfirmed acute MI. Methods and Results Surface ECGs obtained at entry a nd at discharge in patients with confirmed MI enrolled in the GISSI-2 study, a large multicentre trial of different thrombolytic agents, wer e retrieved. Heart rhythm was evaluated and HR was measured; these dat a were then added to the main database of GISSI-2 allowing a complete evaluation of the prognostic significance of HR. patients not in sinus rhythm or with grade 2-3 atrioventricular block were excluded. The pr ognostic significance of HR (cut-offs predefined at 60, 80, 100 beats. min(-1)) at entry for in-hospital mortality and at discharge for 6-mon th mortality was evaluated in the general population and in predefined subgroups. Multivariate analyses were used to assess the independent prognostic value of HR. A total of 8915 patients (more than 70% of the original population) were suitable for the analysis. There was a prog ressive increase in mortality with increasing HR in the general popula tion (from 7.1% for HR <60 beats.min(-1) to 23.4% for HR >100 beats.mi n(-1)) and in the predefined subgroups. Multivariate analysis showed t hat HR exerted an independent prognostic significance. Data for analys is of HR at discharge were available for 7831 patients. Consistent wit h the data observed at entry, a progressive increase of 6-month mortal ity with increasing HR was present in the general population (from 0,8 % for HR <60 beats.min(-1) to 14.3% for HR >100 beats. min(-1)) and fo r the different predefined subgroups. Multivariate analysis confirmed the independent prognostic significance of HR. There was no relation b etween KR and the incidence of fatal and non-fatal reinfarction. Concl usion The present study indicates that HR values from a standard 12-le ad ECG independently predict mortality in patients with acute MI durin g the in-hospital phase and after discharge. This simple index appears very useful for risk stratification in clinical practice.