04-06-2025
Can a Majority of Sudden Cardiac Arrests Be Prevented?
Risk factor modification has long been considered an important strategy for cardiovascular disease prevention. For sudden cardiac arrest (SCA) especially — fatal in 90% of cases — studies have pointed to things like obesity, diabetes, hypertension, and sedentary behavior as essential risk reduction targets.
A recent study in the Canadian Journal of Cardiology provides a focus that has largely been missing in SCA prevention, honing in on the ability to potentially achieve anywhere from a 40%-63% reduction of cases by conservatively or totally eliminating 56 nonclinical risk factors.
Is This Goal Too Lofty?
'When you think about it in practice and from a public health perspective, one would argue that this is unrealistic, almost impossible to achieve,' said Nick Grubic, lead author of the accompanying editorial and a PhD student and methodologist at the Dalla Lana School of Public Health at the University of Toronto in Toronto, Ontario, Canada.
Nick Grubic, PhD
But 'the study points to the importance of modifiable factors in preventing adverse cardiovascular events and chronic diseases and reinforces the need for clinicians to look towards lifestyle interventions as opposed to only focusing on something like pharmacologic management,' Grubic said.
Fodder for SCA Prevention Focus
Utilizing data from over 500,000 UK BioBank participants (mean baseline age, 56.5 years; SD, 8.1 years), the study was geared toward identifying modifiable risk factors associated with SCA incidence.
One of the more novel approaches by the researchers, who are from the School of Public Health at the Fudan University in Shanghai, China, was to address certain limitations of previous studies (for example, short-term effects, residual confounding). They first used an exposome-wide association study design, which allowed them to move from a small number to hundreds of exposures.
This was followed by Mendelian randomization to verify potential causal relationships, facilitating the ability to assess 125 nonclinical exposures across six domains: Lifestyle, psychosocial factors, local environment, physical measures, socioeconomic status, and early life risk factors.
Over an average follow-up of almost 14 years, 0.63% (n = 3147) of participants developed SCA. Fifty-six variables across five domains appeared to be significantly associated with incident SCA, especially lifestyle measures (physical activity, sleep duration, dietary habits, smoking), which drove the largest proportion of SCA risk (13%).
They were followed by physical measures (body mass index, weight, forced expiratory volume in 1 second; 9%), socioeconomic status (employment, social position; 8%), psychosocial factors (employment, mood; 5%), and local environment (5%).
According to the findings, thoroughly eliminating all these 56 risk factors would prevent 63% of SCA cases, while conservatively addressing the riskiest would prevent approximately 40% of cases.
In a related press release, study co-investigator Renjie Chen, PhD, underscored the unexpected benefits.
'We were surprised by the large proportion of SCA cases that could be prevented by improving unfavorable profiles,' he said.
Honing down even further, three risk factors were associated with the most protection: White wine/champagne intake, fruit consumption, and time spent using a computer. Six were associated with the most harm: Fed-up feelings, arm fat mass, arm fat percentage, body mass index, low educational achievement, and systolic blood pressure.
Pointing to one surprising finding — wine/champagne intake — Grubic emphasized the need to be mindful how risk factors like alcohol are measured.
'A lot of it is self-reported information. We really need a little bit more research to confirm a finding like this,' he said.
The same is true of the finding that indicated a protective effect of greater time using the computer.
Jennifer Reed, PhD
'We'd really have to dig into those individuals and acquire more information to tease out this piece,' said Jennifer Reed, PhD, program chair for Cardiac Rehabilitation at the University of Ottawa Heart Institute. 'It's really a web to untangle; for example, they might have higher socioeconomic status or they could have positions that require a higher cognitive load,' said Reed, who was not involved in the study.
Practice Implications
Though novel in design and broad in findings, the study had several limitations.
Both Grubic and Reed pointed specifically to the UK Biobank population, which not only consists mostly of older white adults who are unrepresentative of the general population.
'You really have to be mindful of who is providing the data,' said Reed.
Grubic also said that in order to eliminate a risk factor, a well-defined and realistic intervention must exist. Moreover, erasing one risk factor should not change how the others are distributed.
Other limitations included information and selection biases, as well as potential misclassifications.
The findings confirm the value of lifestyle modification for SCA prevention, and also, provide additional evidence for the American Heart Association's Life's Essential 8 interventions for improving cardiovascular health.
'There needs to be a major shift in how we treat a patient, not only after something occurs (the reaction point or cure aspect), but also from a prevention point of view,' said Reed.
'It's interesting to see that a lot of the factors found to be potentially causally related and protective against SCA in a study like this,' said Grubic, something that Reed noted was vastly different from prior studies that have mostly focused on more traditional risk factors, such as diabetes or hyperlipidemia.
'In the average consulting time, doctors are generally addressing the most acute, urgent concerns first; it doesn't always provide the time for discussions about risk factors for cardiovascular disease,' said Reed. 'It's something that needs to shift a lot.'
Having these conversations is how we start to make an impact on healthcare.
Grubic and Reed reported no relevant financial relationships.
