Two thirds of cases of deadly heart failure are being missed by GPs - amid warnings that an NHS target culture is fuelling a “medical emergency”.

Leading cardiac experts said women and older patients were faring worst, amid “dangerous” failures to spot the life-threatening condition which can be treated with cheap pills.

The major study of almost 100,000 NHS heart failure patients found the vast majority were only diagnosed after they end up being admitted to hospital - by which time they were more likely to be gravely ill.

The Oxford University research, which tracked patients for more than a decade, found a steep decline in the proportion of cases being identified by GPs.

The study found that in 2014, just 36 per cent of patients with heart failure were diagnosed by their GP, or after referral by their family doctor to an outpatient clinic. This was a fall from 56 per cent in 2002.

Researchers said the NHS “pay for performance” scheme for GPs introduced during the period appeared to be contributing to the failings - because key tests are not linked to financial rewards.