Ninety per cent of people with coronary heart disease have at least one other long-term health condition, such as stroke or high blood pressure.
Analysis commissioned by the British Heart Foundation also discovered that 57% of people have at least three inter-related health conditions, which multiple studies have shown increases the risk of early death.
Fifty six per cent of coronary heart disease patients – of which there are 2.3 million in the UK – have high blood pressure, 26% have diabetes and 14% have had a stroke. Thirteen per cent have also suffered heart failure.
The charity claimed that those with the disease were twice as likely to suffer a stroke or develop vascular dementia – which affects 5% of heart patients.
It cited research published in the PLOS Medicine journal, which found the number of heart and circulatory disease patients living with five or more illnesses increased from 6.3% to 24.3% from 2000 to 2014.
The British Heart Foundation said the number of people living with multiple conditions was a major concern for the healthcare system, which is set up to treat individual illnesses.
It suggested more research is needed to consider how conditions like stroke and vascular dementia are connected to help develop treatments for those with multiple health concerns.
Chief executive Simon Gillespie said: “Increasing numbers of people are surviving heart attacks, but are going on to suffer strokes or live with additional conditions like vascular dementia.
“These conditions limit people’s quality of life, increase their risk of dying and will place increasing pressure on the health and care system across the UK.
“We can only reverse this trend by funding more research into all conditions of the heart and circulatory system, with a focus on how they can be treated together. This type of research is currently chronically under-funded but, with more support, we can fund innovative approaches to tackle these conditions head on.”
The data – made up of anonymised medical records from more than 17 million UK patients – was sourced from health information technology firm IQVIA.