Combined High Sensitivity C-Reactive Protein and Maximal Exercise
Tolerance as Predictors of 10-year Mortality among Stable Patients Referred for
Diagnostic Treadmill Stress Testing (2000-2001)

Background: Cardiovascular disease remains the biggest cause of death worldwide especially in the western world including Israel. Exercise capacity measured in metabolic equivalents(METS) and high sensitivity C-reactive protein (hsCRP) can improve the predictive capability of cardiovascular morbidity and mortality. Full evidence regarding the integrated predictive capability of these parameters is lacking. 

Objectives: To examine the independent and the integrated contribution of these functional and inflammatory parameters in predicting all cause mortality during 10 years of follow up. Patients and Methods: 385 stable patients were referred for diagnostic symptom limited treadmill stress testing for suspected/known coronary artery disease in the period between 15/8/2000 and 27/1/2002.Blood samples for hs –CRP  were drawn before initiating exercise testing from all participants. Data regarding all cause mortality during 10 years of follow up after the index date was taken from the medical file and cox regression was performed for risk assessment. In order to examine the integrated contribution of METS and hs CRP, categorical variable was identified expressing the combined profile of the two variables.

Findings: Univariate analysis uploaded significant contribution of the two parameters in predicting all cause mortality. Multivariate analysis showed independent contribution of METS in predicting all cause mortality (HR=0.82 , 95% CI:0.73-0.93, P=0.001).Examining the combined contribution of  METS and hs CRP , The mortality risk is the lowest in the group defined by elevated METS and decreased hs CRP.Compared to this group, the mortality risk is higher with change of any variable (Table 1).Higher  values of hs CRP increase the risk of death by 8.0 among people with higher functional capacity compared to lower values of hs CRP among the same group.<> Conclusions: It is recommended to combine hs CRP test as part of the regular monitoring cardiac patients even among those identified in exercise testing including those with high functional capacity.