NEW DELHI: The Government of India has told Parliament that there is no evidence linking COVID-19 vaccination to the recent spate of sudden cardiac deaths (SCDs) reported among seemingly healthy young individuals across the country. Instead, two government-backed studies attribute the increased risk to a combination of previous COVID-19 hospitalisation, family medical history, and certain high-risk behaviours such as binge drinking, drug use, and intense physical exertion shortly before death.
The clarification came in response to a question raised by Dr Kirsan Namdeo in the Lok Sabha, seeking details on the rise in sudden cardiac deaths among individuals with a history of COVID-19. Health Minister Jagat Prakash Nadda laid a detailed statement on the Table of the House, outlining the steps taken to investigate the phenomenon and the conclusions drawn from two major studies spearheaded by India’s apex medical research institutions.
According to the Indian Council of Medical Research (ICMR), a multi-centre, matched case–control study was conducted by its National Institute of Epidemiology (NIE) between May and August 2023. The study titled “Factors associated with unexplained sudden deaths among adults aged 18-45 years in India” spanned 47 tertiary care hospitals across 19 States and Union Territories. It examined 729 sudden death cases involving adults who were reportedly healthy and without known comorbidities, but who died within 24 hours of hospitalisation or were last seen alive and well 24 hours before their death. These deaths occurred between October 1, 2021, and March 31, 2023.
Each of these cases was compared with four matched controls based on age, gender, and neighbourhood, resulting in a control group of 2,916 individuals. Investigators gathered data on past COVID-19 infection and vaccination, hospitalisation history, family medical background, substance use, alcohol consumption patterns, and physical activity in the two days prior to death or interview.
The study found that individuals who had received two doses of a COVID-19 vaccine had significantly lower odds of suffering unexplained sudden death. In contrast, those who had been hospitalised for COVID-19 in the past faced a higher risk. Similarly, individuals with a family history of sudden death, those who had consumed alcohol in a binge pattern within 48 hours before death or interview, and those who used recreational drugs or engaged in vigorous-intensity exercise shortly before death or interview also had significantly higher odds of dying suddenly.
The government noted that this study provides a statistically robust conclusion that COVID-19 vaccination does not elevate the risk of unexplained sudden death among young Indian adults. Rather, a mix of post-COVID physiological impact, hereditary predisposition, and preventable lifestyle factors appears to be responsible for many of these fatal incidents.
In parallel, a second study titled “Establishing the cause in sudden unexplained deaths in young” was launched by the All India Institute of Medical Sciences (AIIMS), New Delhi, with funding and collaboration from ICMR. Unlike the retrospective design of the NIE study, the AIIMS study is prospective and relies on virtual autopsy methods to investigate the clinical causes of sudden deaths in young adults.
Preliminary findings from the AIIMS study point to heart attacks—specifically myocardial infarctions—as the predominant cause of sudden death in the 18–45 age group. Significantly, the study found no substantial change in the causes of sudden death in the post-pandemic period when compared to earlier years, suggesting that the nature of these fatalities has remained consistent even after COVID-19.
Together, the two studies present the government’s most comprehensive response so far to public anxiety over unexplained cardiac deaths, particularly among young and middle-aged Indians. The findings also aim to counter widespread misinformation and fears about the role of COVID-19 vaccination in such fatalities.
Despite being pressed in Parliament, the Ministry of Health and Family Welfare did not provide a state-wise or Union Territory-wise breakdown of deaths due to cardiac arrest among people with a history of COVID-19. Officials indicated that such granular epidemiological data is still being compiled or not centrally maintained in that format.
