A critical re‐appraisal of different ways of selecting ambulatory patients with suspected heart failure for echocardiography

Abstract

Background: ECG and BNP have been assessed as screening tests for LVSD and heart failure. However, echocardiography also provides information about valvular disease and LVH. We assessed how good these screening tests are in identifying whether the subsequent echocardiogram will have any significant abnormality. Aims: To re-appraise the ECG and BNP as screening tests for echocardiography since there are important practical deficiencies in our current knowledge in this area. Methods: General practitioners referred suspected heart failure patients for clinical assessment, echocardiography, electrocardiography, and BNP measurement. The accuracy of each screening test and combinations of screening tests were calculated for LVSD, heart failure, valvular disease, and LVH. Results: The sensitivities of the ECG for LVSD, heart failure, LVH and valvular disease were 97%, 95%, 76%, and 69%, respectively. The corresponding figures for BNP were 86%, 82%, 59%, and 48%, respectively. When patients with atrial fibrillation and murmurs were excluded, the values for ECG were 94%, 87%, 53%, and 55%, while for BNP they were 83%, 73%, 50%, and 32%. Conclusions: ECG interpretation and BNP are adequate screening tests to detect LVSD or heart failure but fail to screen for other echocardiographic abnormalities, like valvular disease and LVH. This remains the case even if patients with atrial fibrillation or heart murmurs are excluded on the basis that they require echocardiography anyway.

Detection of heart disease by open access echocardiography: a retrospective analysis of general practice referrals

“…Similarly in Holland, 13 the incidence of moderate or severe valve disease was 31% with murmur, 23% with breathlessness and 28% with peripheral oedema. In a Scottish study, 20 the incidence of all valve disease in patients with suspected heart failure was 46% which was substantially higher than the incidence of LV systolic dysfunction, 8%. The incidence of valve disease was similar to the EuroHeart Failure 21 survey, but the study showed that the valve disease was primary in 58 (67%) and secondary in 28 (33%).…”

The Year in Heart Failure

“…However, this combined strategy remains to be tested prospectively, particularly in populations with higher prevalence of cardiac dysfunction in which the yield of a biomarker-based screening strategy may be higher. Even if electrocardiography and natriuretic peptide screening are adequate in determining the probability of the presence of left ventricular systolic dysfunction, the challenge is to adequately screen for other structural abnormalities such as valvular disease or left ventricular hypertrophy that may ultimately lead to progression of cardiac dysfunction (25). Although screening asymptomatic patients at risk, detecting surrogate markers, and initiating early treatment to prevent heart failure appears to be an obvious strategy, there are several challenges that remain: very large sample sizes are needed to demonstrate benefits of early treatment, the most cost-effectiveness manner of screening patients is still unsettled, and the cost of screening is not uniformly covered by insurance or other payers.…”

Potential costs of B-type natriuretic peptide for the identification of people with heart failure in primary care in Scotland – a pilot study

“…However, it should be noted that echocardiography will not only give information about left ventricular function, but also valve function and the presence of left ventricular hypertrophy. 20 Further advantages of BNP relate to its convenience and this was highlighted by a number of GPs who took part in this pilot project. Travelling to a hospital or clinic for echocardiography can be difficult for some patients and almost impossible for others, such as the frail elderly, especially those in nursing homes or those in remote or rural populations.…”

“…20 For comparison, a standard cost for an ECG was assumed to be £30 and an echocardiogram £72. 21 The number of samples generated within the eight GP surgeries and their associated population was extrapolated to estimate the numbers likely to be generated per million population per year.…”