Real-world presentation with heart failure in primary care: do patients selected to follow diagnostic and management guidelines have better outcomes?

'Diagnostic downshift': clinical and system consequences of extrapolating secondary care testing tactics to primary care

Numerous drivers push specialist diagnostic approaches down to primary care ('diagnostic downshift'), intuitively welcomed by clinicians and patients. However, primary care's different population and processes result in under-recognised, unintended consequences. Testing performs poorer in primary care, with indication creep due to earlier, more undifferentiated presentation and reduced accuracy due to spectrum bias and the 'false-positive paradox'. In low-prevalence settings, tests without near-100% specificity have their useful yield eclipsed by greater incidental or false-positive findings. Ensuing cascades and multiplier effects can generate clinician workload, patient anxiety, further low-value tests, referrals, treatments and a potentially nocebic population 'disease' burden of unclear benefit. Increased diagnostics earlier in pathways can burden patients and stretch general practice (GP) workloads, inducing downstream service utilisation and unintended 'market failure' effects. Evidence is tenuous for reducing secondary care referrals, providing patient reassurance or meaningfully improving clinical outcomes. Subsequently, inflated investment in per capita testing, at a lower level in a healthcare system, may deliver diminishing or even negative economic returns. Test cost poorly represents 'value', neglecting under-recognised downstream consequences, which must be balanced against therapeutic yield. With lower positive predictive values, more tests are required per true diagnosis and cost-effectiveness is rarely robust. With fixed secondary care capacity, novel primary care testing is an added cost pressure, rarely reducing hospital activity. GP testing strategies require real-world evaluation, in primary care populations, of all downstream consequences. Test formularies should be scrutinised in view of the setting of care, with interventions to focus rational testing towards those with higher pretest probabilities, while improving interpretation and communication of results.

Use of B-Type Natriuretic Peptide (BNP) and N-Terminal proBNP (NT-proBNP) as Diagnostic Tests in Adults With Suspected Heart Failure: A Health Technology Assessment

BACKGROUND

Heart failure is a complex clinical syndrome that usually presents with breathlessness, leg edema, and fatigue. Clinically measurable natriuretic neurohormones such as B-type natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) are elevated in people with heart failure. We conducted a health technology assessment of BNP and NT-proBNP tests for people with suspected heart failure, which included an evaluation of diagnostic accuracy, clinical impact, cost-effectiveness, the budget impact of publicly funding BNP and NT-proBNP tests, and patient preferences and values.

METHODS

We performed a literature search of previously published systematic reviews of the clinical evidence. We conducted an overview of reviews and included only reviews with a low risk of bias as assessed using the Risk of Bias in Systematic Reviews tool (ROBIS). We excluded any reviews where we found 100% overlap of included primary studies and selected systematic reviews or health technology assessments published after 2006 for inclusion.We performed an economic literature review of BNP and NT-proBNP testing in people with suspected heart failure. Medical and health economic databases were searched from database inception until July 25, 2019. Next, we assessed the cost-effectiveness of BNP and NT-proBNP based on the published economic literature. We transferred the cost-effectiveness results of two applicable, recent economic evaluations from the National Institute for Health and Care Excellence (NICE) to the Ontario setting in lieu of conducting de novo primary economic evaluations. We also estimated the budget impact of publicly funding BNP and NT-proBNP tests in people with suspected heart failure in Ontario over the next 5 years.To contextualize the potential value of BNP and NT-proBNP testing, we spoke with people with suspected heart failure.

RESULTS

We included eight systematic reviews in the clinical evidence review. B-type natriuretic peptides and NT-proBNP had a high pooled sensitivity (80% to 94% and 86% to 96%, respectively; strength of evidence: high) and a low pooled negative likelihood ratio (0.08-0.30 and 0.09-0.23, respectively; strength of evidence: not reported) within varying thresholds or cut points and settings, as reported in seven systematic reviews. In one systematic review, when BNP or NT-proBNP was used in the diagnosis of heart failure in the emergency department (ED), there was a decrease in the mean length of hospital stay (-1.22 days; confidence interval [CI] -2.31 to -0.14; Grading of Recommendations Assessment, Development, and Evaluation [GRADE] Working Group criteria: Moderate). B-type natriuretic peptide testing did not reduce hospital admission rates (odds ratio [OR]: 0.82; CI: 0.67-1.01; GRADE: Moderate), 30-day hospital readmission rates (OR: 0.88; CI: 0.64-1,20; GRADE: Moderate), or hospital mortality rates (OR: 0.96; CI: 0.65-1.41; GRADE: Moderate). No systematic review was identified that addressed the impact on clinical outcomes of BNP use in the community setting.Our economic literature review found a total of 12 studies evaluating the cost-effectiveness of BNP or NT-proBNP testing in patients with suspected heart failure. The studies suggested that BNP or NT-proBNP tests, when used in addition to standard clinical investigations, were either dominant (less costly and more effective) or cost-effective across different countries (including Canada) and settings.Two economic evaluations conducted by NICE were considered applicable to our research question and of high methodological quality. Based on the transferred results from the two NICE economic evaluations, we concluded that BNP and NT-proBNP were highly likely to be cost-effective in Ontario in the ED setting, and NT-proBNP was highly likely to be cost-effective in the community care setting.Our budget impact analysis estimated that over the next 5 years, publicly funding BNP and NT-proBNP tests would result in an additional cost of $38 million in the ED (at a cost of $75 per test) and a cost savings of $20 million in community care (at a cost of $28 per test).We received strong support from interview participants about BNP or NT-proBNP diagnostic testing. The main reason was the perceived potential benefit of receiving a speedier diagnosis. The overall process, from diagnosis to treatment, is a substantial emotional burden for patients and caregivers, and for those living further away from secondary or tertiary care settings. An earlier diagnosis could allow patients to receive treatment at a hospital better equipped to manage their potentially fatal symptoms and conditions.

CONCLUSIONS

B-type natriuretic peptide and NT-proBNP tests have high sensitivity and low negative likelihood ratio, suggesting that concentrations of either natriuretic peptides within the appropriate cut points can rule out the presence of heart failure with a high degree of confidence. Additionally, BNP or NT-proBNP testing along with usual care in an ED setting likely can reduce the length of hospital stay by at least 1 day but likely results in little to no difference in hospital mortality, 30-day readmission, or admission rates to hospital.Based on the published economic literature, we expected BNP or NT-proBNP tests used in addition to standard clinical investigations to be cost-effective as a rule-out test in patients with suspected heart failure in Ontario. If BNP and NT-proBNP tests are publicly funded in Ontario, we estimated that there would be additional costs in the ED setting (due to increased detection of heart failure) and savings in community care (due to reduced referrals to echocardiography and cardiologists).People we interviewed gave BNP and NT-proBNP testing strong support, citing the perceived benefits of quicker, more accurate diagnoses that could reduce misdiagnoses, stress, and the burden on patients and caregivers.

Heart failure epidemiology and treatment in primary care: a retrospective cross-sectional study

Aims

Heart failure is one of the leading causes of morbidity and mortality worldwide, but little is known on heart failure epidemiology and treatment in primary care. This study described patients with heart failure treated by general practitioners, with focus on drug prescriptions and especially on the only specific treatment for heart failure with reduced ejection fraction, namely sacubitril/valsartan.

Methods and results

This was a retrospective cross‐sectional study using data from an electronic medical record database of Swiss general practitioners from 2016 to 2019. Multilevel logistic regression was used to find determinants of sacubitril/valsartan prescription; odds ratios (ORs) and 95% confidence intervals (CIs) were reported. We identified 1288 heart failure patients (48.5% women; age: median 85 years, interquartile range 77–90 years) by means of diagnosis code, representing 0.5% of patients consulting a general practitioner during the observation period. About 73.6% received a renin–angiotensin–aldosterone system inhibitor, 67.8% a beta‐blocker, 34.6% a calcium channel blocker, 86.1% a diuretic, and 40.1% another cardiac drug. Sacubitril/valsartan was prescribed in 6% predominantly male patients (OR 2.10, CI 1.25–3.84), of younger age (OR 0.59 per increase in 10 years, CI 0.49–0.71), with diabetes mellitus (OR 1.76, CI 1.07–2.90). The recommended starting dose for sacubitril/valsartan was achieved in 67.1% and the target dose in 28.6% of patients.

Conclusions

Prevalence of heart failure among patients treated by general practitioners was low. Considering the disease burden and association with multimorbidity, awareness of heart failure in primary care should be increased, with the aim to optimize heart failure therapy.