Stress echocardiography is a safe and effective first-line test for suspected coronary artery disease in patients over 80, a UK study, published in Heart, has found.

A total of 374 consecutive patients, 46% men, aged 83.6 (±3.0) years who underwent stress echo for evaluation of coronary artery disease were studied. The researchers looked at feasibility, diagnostic accuracy and safety of the test. Patients were followed up for 4.0 ± 2.0 years for all cause mortality, cardiovascular deaths and non-fatal myocardial infarction (MI).

The vast majority, 360 (96.2%) of the 374 tests, were diagnostic.

There were 50 patients with inducible ischaemia of whom 33 (66%) proceeded to angiography. More than three-quarters, 27 (82%) of these patients had significant coronary artery disease.

During follow-up, there were 127 deaths (36%) and 36 non-fatal MIs (10%). Annualised mortality, non-fatal MI and combined mortality/non-fatal MI rates were 8.1%, 1.8% and 9.4% respectively for patients with a normal stress echo and 12.1%, 5.5% and 14.1% respectively for those with an abnormal stress echo.

The key predictors of non-fatal MI were:

• Prior coronary artery disease;

HR 2.89 (95% CI: 1.03-8.15; P = 0.045)

• Peripheral vascular disease;

HR 3.33 (95% CI: 1.18-9.45, P = 0.02)

• Inducible ischaemia on stress echo;

HR 3.97 (95% CI: 1.49-10.55, P = 0.006). The greater the extent of ischaemia, the higher the incidence of non-fatal MI.

There were no major complications during stess echo (i.e. no patients developed serious ventricular arrhythmias, acute MI or died).

Stress echo has established itself as the preferred initial diagnostic test for the investigation of chest pain where coronary artery disease is suspected.

It has effectively superseded the exercise ECG/exercise tolerance test.

The reasons for this include cost effectiveness, diagnostic accuracy, availability, lack of ionising radiation, patient tolerability and endorsement by guidelines and national bodies such as NICE. If additional roles such as assessing valve disease and myocardial viability are also considered then there would appear to be a clear role for stress echo for many years to come.

Prognostic value is an aspect of the test that can often be overlooked.

This has been established in younger populations but it had been postulated that prognostic value may be less apparent in more elderly populations because of their shorter life expectancy and the presence of important comorbidities.

This study provides reassurance that stress echo is a safe and effective first-line test for suspected coronary artery disease in elderly populations.

The authors conclude: ‘Stress echo had excellent feasibility and safety in the octogenerian population, and had excellent positive predictive value for flow-limiting coronary artery disease and influenced subsequent revascularsation.

‘During long-term follow-up, stress echo parameters were the strongest independent predictors of non-fatal MI and cardiovascular events, and an abnormal stress echo was associated with a 50% increase in mortality.’

Dr Peter Savill