OBJECTIVES: We sought to determine whether chronotropic incompetence (CI) adds incremental value in predicting cardiac death (CD) and all-cause mortality and to determine which marker of CI is superior. BACKGROUND: Chronotropic incompetence, defined by either a low percent heart rate (HR) reserve achieved or failure to achieve 85% maximal age-predicted heart rate (MA-PHR), is a predictor of mortality. These variables have not been examined together in a comprehensive myocardial perfusion single-photon emission computed tomographic (SPECT), or MPS, model. METHODS: A total of 10,021 patients who underwent exercise MPS, evaluated by a summed stress score (SSS), were followed up for 719 +/- 252 days. Percent HR reserve = (peak HR - rest HR)/(220 - age - rest HR) x 100, with <80% considered abnormal. RESULTS: A total of 2,956 patients (29.5%) had low %HR reserve; 1,331 (13.3%) achieved <85% MA-PHR; and 1,296 (13.0%) had both. There were 234 deaths (93 CDs). On multivariate analysis, the SSS, %HR reserve, and inability to achieve 85% MA-PHR were predictors of all-cause mortality and CD (all p < 0.01). Myocardial perfusion SPECT was the most powerful predictor of CD (chi-square = 50). When the %HR reserve and ability to achieve 85% MA-PHR were considered, only the former remained a predictor of CD (p = 0.006 vs. p = 0.59). CONCLUSIONS: In a comprehensive MPS model, CI was an important predictor of CD and all-cause mortality. Percent HR reserve was superior to the ability to achieve 85% MA-PHR in predicting CD; MPS was superior to both. Combined with previous studies, the findings suggest that %HR reserve should become the standard for assessing the adequacy of HR response during exercise testing, and that it should be routinely incorporated in risk stratification algorithms.
OBJECTIVES: We sought to determine whether chronotropic incompetence (CI) adds incremental value in predicting cardiac death (CD) and all-cause mortality and to determine which marker of CI is superior. BACKGROUND: Chronotropic incompetence, defined by either a low percent heart rate (HR) reserve achieved or failure to achieve 85% maximal age-predicted heart rate (MA-PHR), is a predictor of mortality. These variables have not been examined together in a comprehensive myocardial perfusion single-photon emission computed tomographic (SPECT), or MPS, model. METHODS: A total of 10,021 patients who underwent exercise MPS, evaluated by a summed stress score (SSS), were followed up for 719 +/- 252 days. Percent HR reserve = (peak HR - rest HR)/(220 - age - rest HR) x 100, with <80% considered abnormal. RESULTS: A total of 2,956 patients (29.5%) had low %HR reserve; 1,331 (13.3%) achieved <85% MA-PHR; and 1,296 (13.0%) had both. There were 234 deaths (93 CDs). On multivariate analysis, the SSS, %HR reserve, and inability to achieve 85% MA-PHR were predictors of all-cause mortality and CD (all p < 0.01). Myocardial perfusion SPECT was the most powerful predictor of CD (chi-square = 50). When the %HR reserve and ability to achieve 85% MA-PHR were considered, only the former remained a predictor of CD (p = 0.006 vs. p = 0.59). CONCLUSIONS: In a comprehensive MPS model, CI was an important predictor of CD and all-cause mortality. Percent HR reserve was superior to the ability to achieve 85% MA-PHR in predicting CD; MPS was superior to both. Combined with previous studies, the findings suggest that %HR reserve should become the standard for assessing the adequacy of HR response during exercise testing, and that it should be routinely incorporated in risk stratification algorithms.
Authors: Daniel S Berman; Xingping Kang; Piotr J Slomka; James Gerlach; Ling de Yang; Sean W Hayes; John D Friedman; Louise E J Thomson; Guido Germano Journal: J Nucl Cardiol Date: 2007-07 Impact factor: 5.952
Authors: Sonia Franciosi; Thomas M Roston; Frances K G Perry; Bjorn C Knollmann; Prince J Kannankeril; Shubhayan Sanatani Journal: J Cardiovasc Electrophysiol Date: 2019-07-11
Authors: Arthur N Westover; Paul A Nakonezny; Carolyn E Barlow; Wanpen Vongpatanasin; Bryon Adinoff; E Sherwood Brown; Eric M Mortensen; Ethan A Halm; Laura F DeFina Journal: J Psychiatr Res Date: 2015-03-21 Impact factor: 4.791