After Valve Surgery, More Physical Activity Tied to Lower Mortality
Patients who engage in at least moderate physical activity in the 6 to 12 months after undergoing valve surgery are more likely to be alive up to 2 years later, according to observational data from Denmark. Moreover, those formally participating in a postsurgery cardiac rehab program are more likely to reach that level of exercise.
Study coauthor Kirstine L. Sibilitz, MD, PhD (Rigshospitalet—Copenhagen University Hospital, Denmark), cautioned to TCTMD that the prospective cohort study was intended only to investigate any potential associations. Its design, which involved surveying patients by mail and ascertaining outcomes from nationwide registries, precludes any judgment on causal relationships, she said.
“It is true that the findings are probably influenced by comorbidity, eg, that people with more comorbidities physically and psychologically (such as having anxiety) tend to be less physically active,” Sibilitz acknowledged in an email. But she emphasized the analysis did attempt to adjust for such confounders.
Along with lead author Ken Lund (Holbæk Hospital, Denmark), Sibilitz and others published their findings online in Heart.
Rehab Appears to Have a Positive Influence
Lund et al identified 867 Danish adults who underwent valve surgery during the first half of 2011. Among 742 eligible patients sent the CopenHeart survey by mail, 557 responded with details about their level of physical activity at 6 to 12 months postsurgery. Outcomes were obtained from the Danish National Patient Register and Danish Civil Registration System.
Respondents with low activity were significantly more likely to be female, aged at least 76 years, unmarried, and have severe comorbidity (Charlson score ≥ 2).
Approximately six in 10 patients who took the survey were formally enrolled in an exercise-based cardiac rehab program. Those who participated in rehab were more likely than nonparticipants to have a moderate or high level of physical activity level (adjusted OR 1.52; 95% CI 1.03-2.24), irrespective of age or sex.
By follow-up at 18-24 months, 16 patients had died. Patients engaging in a moderate-to-high amount of physical activity had a lower risk of mortality than those with low activity (1% vs 5.5%; adjusted HR 0.19, 95% CI 0.05-0.70). Again, the association was not modified by age or sex. However, no difference in the risk of readmission, whether acute or planned, was seen.
Women, Older Patients Merit Attention
“Because of our study design, we cannot examine the causal and temporal relationships between exercise-based cardiac rehabilitation and long-term physical activity level,” the investigators write, though they note that the findings do align with those of earlier studies. “Valve surgery and exercise training may both influence the physical activity level, and their separate effects should ideally be investigated in future cohort studies or randomized clinical trials.”
To TCTMD, Sibilitz pointed out that European guidelines recommend that patients be referred to cardiac rehab after valve surgery.
Clinicians should keep the benefits of physical activity in mind for this group, she advised. Referral should not be done indiscriminately but rather on an individual basis, considering factors such as comorbidities and LVEF, postsurgery recovery, and valve type. “Special care should be taken towards unstable patients and patients with concomitant heart failure,” Sibilitz noted. “Where in doubt, testing should be performed to investigate how the patient tolerates physical activity."
The findings also emphasize “the need to focus on women and older people in exercise-based cardiac rehabilitation, since they are often underrepresented,” the investigators note in their paper.
- Lund K, Sibilitz KL, Berk SK, et al. Physical activity increases survival after heart valve surgery. Heart. 2016;Epub ahead of print.
- Lund and Sibilitz report no relevant conflicts of interest.