Value of an Exercise Workload ≥10 Metabolic Equivalents for Predicting Inducible Myocardial Ischemia

Abstract

Background-We sought to identify extensive ischemia on exercise echocardiography (ExE) relative to workload in patients without known coronary artery disease and to investigate whether ExE is useful in predicting outcomes in those with high exercise capacity (≥10 metabolic equivalents [METs]) plus a maximal test (≥85% of their maximal age-predicted heart rate [MAPHR]). Methods and Results-The analysis was performed on 4269 patients who underwent ExE, of whom 3995 achieved ≥85% of their MAPHR. These patients were divided according to the reached workload (<7, 7-9, or ≥10 METs) and compared for ExE results. Outcomes in the group achieving ≥10 METs plus ≥85% of their MAPHR (n=2221) were specifically assessed. Ischemia was defined as new/worsening wall motion abnormalities with exercise. ExE results were different between groups because the METs were lower. Still, among patients achieving ≥10 METs plus ≥85% of their MAPHR, 9.3% had extensive ischemia and 6% multiterritory disease. During follow-up in this subgroup, 108 patients died and 42 had a major cardiac event. Annualized mortality and major cardiac event rates were 0.84% and 0.32% in patients without ischemia versus 2.26% and 0.84% in those with ischemia, respectively (P<0.001 and P=0.002, respectively). Ischemia was an independent predictor of mortality (hazard ratio,

Abnormal exercise echocardiography plus abnormal E/e′ ratio at exercise portends worse outcome in patients with dyspnea

“…However, the event rate was higher than expected in a population of these characteristics. For instance, in a previous ExE study by our group, the annualized mortality rate for patients with suspected coronary artery disease (CAD) due to mainly chest pain, with similar percentages of ischemia (19%) and resting WMAs (13%), and a similar achieved maximal workload of 7-9 METs, was just 2.2% [13]. In another study on patients with either angina or dyspnea referred for ExE, cardiac events were also more than double in those with dyspnea [14].…”

“…The septal e 0 measurement could have led to diminished values in patients with WMAs at this level. However, this approach has also been used in other ExE studies [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19], so it might be useful for comparisons. Besides E/e 0 values, assessment of pulmonary artery pressures by Doppler at the tricuspid level may be valuable for studying these patients.…”

Estratificación de riesgo de muerte a mediano plazo de pacientes evaluados por enfermedad coronaria con SPECT de perfusión miocárdica bajo efecto de dipiridamol

“…El estrés con ejercicio es preferido en pacientes capaces de lograr al menos 5 equivalentes metabólicos (METS) y alcanzar 85% de la frecuencia cardíaca máxima teórica para la edad (FCMT), ya que los efectos fisiológicos pueden ser observados directamente 20 , se aprovechan los datos aportados por la prueba de esfuerzo; también esta es predictora independiente de sobrevida, especialmente al alcanzar 10 o más METS 21 . En un gran estudio de ecocardiografía con estrés físico 22 , se encontraron tasas de mortalidad cardíaca anuales de 2,26% y 0,84% en pacientes con y sin isquemia, con tasas de eventos cardíacos mayores en el grupo con isquemia de 0,84% versus 0,32% en los sin esta, en los que alcanzaron 10 METS y respuesta máxima (> 85% de su FCMT). En una pequeña experiencia nuestra con 121 pacientes en evaluación de EC capaces de alcanzar 10 METS se encontró isquemia en 24,8% y baja tasa de eventos cardiovasculares durante seguimiento promedio de 33 meses 23 .…”

Seguimiento clínico en pacientes con buena capacidad metabólica en la prueba de esfuerzo con SPECT miocárdico

“…Las bajas tasas observadas parecieran limitar la utilidad de la técnica para evaluar eventos 22 . Aunque nuestra casuística es limitada por el tipo de pacientes, la tasa de eventos mayores fue más alta (1,7%) que la descrita 16 .…”