Is cardiac function impaired in premotor Parkinson's disease? A retrospective cohort study.

The objective of this study was to assess cardiovascular response during cardiac stress testing in neurologically asymptomatic individuals who developed motor features of Parkinson's disease several years after the cardiac stress testing. This was a retrospective cohort study of patients who underwent cardiac stress testing between January 2001 and December 2010. Patients were followed until May 2012 to select those who developed Parkinson's disease. Heart rate and blood pressure both at rest and at peak exercise and heart rate variability at rest were recorded. For each patient who developed Parkinson's disease, 2 matched controls who did not develop Parkinson's disease at the end of the follow-up period were selected. Patients who were diagnosed with Parkinson's disease the same day of cardiac stress testing also were selected for comparison purposes. After excluding participants who were lost to follow-up, 2739 patients remained. From this cohort, 18 (11 men) had developed Parkinson's disease 4.27 ± 2.56 years after the cardiac stress test. Thirty-six matched controls were selected. At peak exercise, the maximum heart rate and the percentage of theoretical maximum heart rate were significantly lower in patients who developed Parkinson's disease after cardiac stress testing compared with controls. The sensitivity of a maximum heart rate ≤ 143 beats per minute to predict a diagnosis of Parkinson's disease after a mean of 4.27 years was 83%, and the specificity was 62%. The results from this exploratory study demonstrate that chronotropic insufficiency may constitute an early sign of Parkinson's disease during the premotor phase, serving as potential risk factor for its diagnosis. Further investigations are needed in larger populations. © 2013 Movement Disorder Society.