Ambulatory Surveillance of Patients Referred for Cardiac Rehabilitation Following Cardiac Hospitalization: A Feasibility Study

Purpose: To examine the feasibility of implementing an ambulatory surveillance system for the monitoring of patients referred to cardiac rehabilitation following cardiac hospitalizations. Methods: This study consists of 1208 consecutive referrals to cardiac rehabilitation between October 2007 and April 2008. Patient attendance to cardiac rehabilitation, waiting-times for cardiac rehabilitation, and adverse events while waiting for cardiac rehabilitation were tracked by telephone surveillance by a nurse. Results: Among the 1208 consecutive patients referred, only 44.7% of referred patients attended cardiac rehabilitation; 36.4% of referred patients were known not to have attended any cardiac rehabilitation, while an additional 25.8% of referred patients were lost to follow-up. Among the 456 referred patients who attended the cardiac rehabilitation program, 19 (4.2%) experienced an adverse event while in the queue (13 of which were for cardiovascular hospitalizations with no deaths) with mean waiting times of 20 days and 24 days among those without and with adverse events, respectively. Among the 440 referred patients who were known not to have attended any cardiac rehabilitation program 114 (25.9%) had adverse clinical events while in the queue; 46 (10.4%) of these events required cardiac hospitalization and 8 (2%) patients died. Conclusions: Ambulatory surveillance for cardiac rehabilitation referrals is feasible. The high adverse event rates in the queue, particularly among patients who are referred but who do not attend cardiac rehabilitation programs underscores the importance of ambulatory referral surveillance systems for cardiac rehabilitation following cardiac hospitalizations

Functional capacity and heart rate response: associations with nocturnal hypertension

Abstract Background Absences of normative, 10–20 % declines in blood pressure (BP) at night, termed nocturnal non-dipping, are linked to increased cardiovascular mortality risks. Current literature has linked these absences to psychological states, hormonal imbalance, and disorders involving hyper-arousal. This study focuses on evaluating associations between nocturnal non-dipping and indices of functional cardiac capacity and fitness. Methods The current study was a cross-sectional evaluation of the associations between physical capacity variables e.g. Metabolic Equivalent (MET) and Maximum Heart Rate (MHR), Heart rate reserve (HRR), and degree of reduction in nocturnal systolic blood pressure (SBP) or diastolic blood pressure (DBP), also known as ‘dipping’. The study sample included 96 cardiac patient participants assessed for physical capacity and ambulatory blood pressure monitoring. In addition to evaluating differences between groups on nocturnal BP ‘dipping’, physical capacity, diagnoses, and medications, linear regression analyses were used to evaluate potential associations between nocturnal SBP and DBP ‘dipping’, and physical capacity indices. Results 45 males and 14 females or 61.5 % of 96 consented participants met criteria as non-dippers (<10 % drop in nocturnal BP). Although non-dippers were older (p = .01) and had a lower maximum heart rate during the Bruce stress test (p = .05), dipping was only significantly associated with Type 2 Diabetes co-morbidity and was not associated with type of medication. Within separate linear regression models controlling for participant sex, MHR (β = 0.26, p = .01, R2 = .06), HRR (β = 0. 19, p = .05, R2 = .05), and METs (β = 0.21, p = .04, R2 = .04) emerged as significant but small predictors of degree of nighttime SBP dipping. Similar relationships were not observed for DBP. Conclusions Since the variables reflecting basic heart function and fitness (MHR and METs), did not account for appreciable variances in nighttime BP, nocturnal hypertension appears to be a complex, multi-faceted phenomena