Therapeutic implications of low lymphocyte count in non-ST segment elevation acute coronary syndromes.
BACKGROUND
Low lymphocyte count (LLC), a surrogate for inflammation, has emerged as a potential risk factor for cardiovascular outcomes, especially new ischemic events. To identify patients with non-ST segment elevation acute coronary syndromes (NSTEACS) who benefit from an invasive revascularization strategy remains a challenge. We sought to determine if patients with high-risk NSTEACS who exhibited LLC have a greater reduction in long-term post-discharge myocardial infarction (MI) when managed under a revascularization invasive strategy (RIS) as compared with conservative strategy (CS).


METHODS
Nine hundred seventy two consecutive patients with high-risk NSTEACS were treated under two revascularization strategies (RS): 1) CS, from January 2001 to October 2002 (345 patients; 35.5%) and 2) RIS, from November 2002 to May 2005 (627 patients; 64.5%). LLC was defined as lymphocytes count < or =1200 cells/ml (1 vs. 2-4 quartiles). The association between the type of RS and MI was stratified by lymphocyte count status and assessed by Cox regression adapted for competing events.


RESULTS
At 3-year follow-up, 145 deaths (14.9%), 135 MI (13.9%) and 76 revascularization procedures (7.8%) were registered. In a multivariable setting, LLC patients exhibited a greater MI risk reduction when managed under RIS (HR: 0.40; 95% CI=0.22-0.72, p=0.003). Conversely, when LLC was not present, no difference in the rate of MI was detected between the two RS.


CONCLUSIONS
LLC identifies a subgroup of patients with greater reduction in the risk of postdischarge MI when a RIS is applied.
Núñez
Julio
J
Servicio de Cardiología, Hospital Clínico Universitario, Universitat de Valencia, Valencia, Spain. yulnunez@gmail.com
Sanchis
Juan
J
Bodí
Vicent
V
Núñez
Eduardo
E
Heatta
Anne M
AM
Miñana
Gema
G
Merlos
Pilar
P
Rumiz
Eva
E
Palau
Patricia
P
Sanjuán
Rafael
R
Blasco
Maria L
ML
Llàcer
Angel
A
D054058:Acute Coronary Syndrome / Q000175:diagnosis / Q000276:immunology* / Q000401:mortality / Q000601:surgery / Q000628:therapy; D000368:Aged; D004562:Electrocardiography; D005260:Female; D006801:Humans; D018655:Lymphocyte Count; D008231:Lymphopenia / Q000150:complications; D008297:Male; D009203:Myocardial Infarction / Q000209:etiology / Q000276:immunology; D009204:Myocardial Revascularization / Q000009:adverse effects* / Q000401:mortality; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome