New tests can diagnose ‘hidden’ heart diseases  - such as microvascular angina - caused by problems with the small blood vessels supplying the heart, according to research funded by the British Heart Foundation presented at the Transcatheter Cardiovascular Therapeutics (TCT) conference in San Diego.

The new tests are not yet standard in the NHS because, before now, there has not been enough evidence gathered about whether they would benefit patients. Now, researchers say that they should be routinely available to pinpoint the cause of chest pain.

Researchers from the University of Glasgow and Golden Jubilee National Hospital performed the new ‘small vessel’ test which involves passing a thin, flexible wire into the heart and measuring how well a blood vessel relaxes.

The team performed the new test on 151 patients with chest pain who could not be diagnosed using currently available tests. The small vessel test results for half of the patients were made available to doctors to further guide the diagnosis and treatment, whereas, in the other half of the patients, the results were not disclosed. These patients followed standard care. The team found that the new tests were able to correctly diagnose up to four times as many patients as standard tests.

Even more importantly, six months later, symptoms of angina were less and quality of life was better in the patients whose care was guided by the new tests.

Angina is often triggered during exercise, cold weather and emotional stress and points to an underlying problem in the heart.

Doctors commonly recommend an angiogram, an invasive procedure which looks for narrowing of the heart’s main arteries. However, in around one-half of patients with angina, this angiogram reveals no significant problems. Despite this, patients can experience severe chest pain and have a significantly higher risk of having a heart attack in the future.