Predictors of impaired heart rate variability and clinical outcome in patients with acute myocardial infarction treated by primary angioplasty.
OBJECTIVE
To investigate the determinants and prognostic value of heart rate variability (HRV) in acute myocardial infarction (AMI) patients treated by percutaneous coronary intervention (PCI).


METHODS
We studied 64 patients with AMI (58.4 +/- 10 years, 56 men), treated by PCI within 12 h of symptom onset. Patients underwent 24-h electrocardiographic Holter recording before discharge. HRV was measured in the time- and frequency-domain. Cardiac events were assessed at 6 months.


RESULTS
At univariate analysis, Thrombolysis in Myocardial Infarction (TIMI) flow grade < 3 was significantly predictive of reduced frequency-domain variables. On multivariate analysis, diabetes and pre-PCI time > 6 h were the strongest predictors of depressed HRV, with peak creatine kinase myocardial-type and lower left ventricular ejection fraction being also variably correlated with impaired HRV. At 6-month follow-up, seven patients (10.1%) had cardiac events (one AMI, six revascularization procedures). A low standard deviation of RR intervals was a significant predictor of events (P = 0.009), although only age was associated with the endpoint (P = 0.05) on multivariate analysis.


CONCLUSIONS
Our study shows that, in AMI patients treated by primary PCI, a delay in coronary revascularization and AMI extension are key factors for determining depressed HRV.
Larosa
Claudio
C
Istituto di Cardiologia, Università Cattolica del Sacro Cuore, Roma, Italy.
Sgueglia
Gregory Angelo
GA
Sestito
Alfonso
A
Infusino
Fabio
F
Niccoli
Giampaolo
G
Lamendola
Priscilla
P
Mariani
Luca
L
Santangeli
Pasquale
P
Lombardo
Antonella
A
Crea
Filippo
F
Lanza
Gaetano Antonio
GA
D015906:Angioplasty, Balloon, Coronary / Q000379:methods*; D015716:Electrocardiography, Ambulatory; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000503:physiopathology*; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000503:physiopathology / Q000628:therapy*; D011379:Prognosis