Sudden cardiac death (SCD) refers to the sudden and unexpected lethal rhythm disturbance of the heart causing cardiac arrest and leading to death unless the person receives cardio-pulmonary resuscitation (CPR) or defibrillation (a shock). Implantable cardioverter defibrillators (ICDs) are implanted shock box devices, similar to pacemakers, that shock one’s heart during cardiac arrest back to normal heart rhythm and thus save lives, but assigning them to the correct people is a challenge yet to be solved. Currently guidelines assign ICDs based on how weak someone’s heart is or if one has previously survived a cardiac arrest. Most people that have SCD have “normal” hearts and for that reason we need to rethink how to assign ICDs.
We plan to use the CPRD data set to:
A. Define the scale of SCD in the UK over time
B. Describe disparities in diagnosis of known predisposing diseases
C. Discern risk factors that contribute to developing SCD
D. Discern factors associated with SCD survival
E. Describe what SCD survival looks like in terms of subsequent disease development
The study aims to perform a retrospective real-world study, using linked CPRD, Hospital Episodes Statistics and Office of National Statistics mortality data to describe annualised incidence rates of predisposing SCD conditions, SCD diagnosis and mortality, SCD risk and protective factors and subsequent disease course following SCD survival. Incidence rates will be presented accounting for temporal changes in risk factors using age-adjusted Poisson regression models and stratified by disease type, sex, ethnicity and region. Regression analyses will be used to assess whether novel co-morbidities are associated with SCD event and whether this association differs between ethnicities, sex, SES and regions using a comparator cohort of 500K CPRD heart failure patients without SCD. Factors associated with SCD survival will be identified by comparing fatal and non-fatal SCD using adjusted regression analyses. Flexible parametric survival models will be used to investigate the association between SCD survival and subsequent risk of heart failure, cerebrovascular disease, renovascular disease, mental health disorders or mortality by comparing the comparator heart failure cohort without SCD.
Outcomes to be Measured
● SCD incidence crude, adjusted and stratified
● SCD survival by relative risk
● SCD risk factors for correlation coefficient, R squared and p values
Joseph Barker - Chief Investigator - University of Leicester
Joseph Barker - Corresponding Applicant - University of Leicester
Atanu Bhattacharjee - Collaborator - University of Leicester
Clare Gillies - Collaborator - University of Leicester
HES Admitted Patient Care;ONS Death Registration Data;Practice Level Index of Multiple Deprivation