¿La prueba del frío podría predecir la aparición de eventos cardiovasculares en pacientes sin enfermedad coronaria demostrada?;
Is Cold Pressor Test Useful to Predict Cardiovascular Events in Patients with Not Documented Coronary Artery Disease?

RESUMENIntroducciónLa disfunción endotelial es la primera alteración conocida que interviene en el desarrollo de la cardiopatía isquémica. La falta de metodologías adecuadamente desarrolladas que permitan reconocer en la etapa preclínica de la enfermedad a los pacientes en riesgo de padecer un evento cardiovascular alertan sobre la necesidad de adoptar métodos adicionales de diagnóstico para su identificación precoz. La función endotelial en las arterias coronarias fue evaluada con perfusión miocárdica SPECT y la prueba del frío.ObjetivosDeterminar la prevalencia de la prueba del frío en 511 pacientes sin cardiopatía isquémica demostrada, como también de los factores de riesgo coronario asociados en aquellos con resultado positivo y analizar la incidencia de eventos cardiovasculares en un seguimiento de cincuenta meses.

SUMMARY To determine the prevalence of the cold pressor test in 511 patients with no proved ischemic heart disease, as well as, the associated coronary risk factors in those patients with a positive result and to analyze the incidence of cardiovascular events in a 50-month monitoring.Material and MethodsA tomographic study of myocardial perfusion SPECT imaging was performed in 511 patients in a department of nuclear medicine, whose result versus the exercise showed uniform radiotracer uptake. No patient had history of myocardial revascularization or previous myocardial infarction. The cold pressor test was performed within 5 days after the admission protocol. The test is positive when radioisotope hypo-uptake is observed at any segment that was not present in the cardiac stress test and it is negative when there are no changes in the uptake between both studies.The average monitoring was 24±13 months, which could be completed in 95% of the patients. Cardiac mortality, myocardial infarction, cerebrovascular accident and revascularization procedures were analyzed.ResultsThe mean age was 58.7 years with a prevalence of 52.6% in men. Prevalence of risk factors: diabetes 10.3%, dyslipidemia 69.3%, hypertension 63.4%, obesity 25.2%, and tobacco smoking 22.3%.The test was positive in 32.4% of the patients. 3.9% of the patients did not tolerate a cold stimulus and 5.3% had vasovagal response.During 50 months, the event-free survival was 95.6% and 86.6% in patients with negative and positive test, respectively (p < 0.01).ConclusionsThe prevalence of the positive cold pressor test in patients with no proved ischemic heart disease was 32.4%. Men and high body mass index were associated with a positive test. The positive cold pressor test would identify patients who could suffer from cardiovascular events.REV ARGENT CARDIOL 2010;78:417-424.    Objective