Selecting the Best Noninvasive Imaging Test to Guide Treatment After an Inconclusive Exercise Test

Real-world evidence study on the impact of SPECT MPI, PET MPI, cCTA and stress echocardiography on downstream healthcare utilisation in patients with coronary artery disease in the US

BACKGROUND

Coronary artery disease (CAD) is associated with a large clinical and economic burden. However, consensus on the optimal approach to CAD diagnosis is lacking. This study sought to compare downstream healthcare resource utilisation following different cardiac imaging modalities, to inform test selection for CAD diagnosis.

METHODS

Claims and electronic health records data from the Decision Resources Group Real-World Evidence US Data Repository were analysed for 2.5 million US patients who underwent single-photon emission computed tomography myocardial perfusion imaging (SPECT MPI), positron emission tomography myocardial perfusion imaging (PET MPI), coronary computed tomography angiography (cCTA), or stress echocardiography between January 2016 and March 2018. Patients were stratified into nine cohorts based on suspected or existing CAD diagnosis, pre-test risk, and prior events or interventions. Downstream healthcare utilisation, including additional diagnostic imaging, coronary angiography, and cardiac-related health system encounters, was compared by cohort and index imaging modality.

RESULTS

Among patients with suspected CAD diagnosed within 3 months of the index test, PET MPI was associated with lower downstream utilisation; 25-37% of patients who underwent PET MPI required additional downstream healthcare resources compared with 40-49% of patients who received SPECT MPI, 35-41% of patients who underwent cCTA, and 44-47% of patients who received stress echocardiography. Patients who underwent PET MPI experienced fewer acute cardiac events (5.3-9.4%) and generally had lower rates of healthcare encounters (0.8-4.1%) and invasive coronary angiography (ICA, 15.4-24.2%) than those who underwent other modalities. SPECT MPI was associated with more downstream ICA (31.3-38.2%) and a higher rate of cardiac events (9.5-13.2%) compared with PET MPI (5.3-9.4%) and cCTA (6.9-9.9%). Across all cohorts, additional diagnostic imaging was 1.6 to 4.7 times more frequent with cCTA compared with PET MPI.

CONCLUSION

Choice of imaging modality for CAD diagnosis impacts downstream healthcare utilisation. PET MPI was associated with lower utilisation across multiple metrics compared with other imaging modalities studied.

Patient selection essential for computed tomography coronary angiography

OBJECTIVE

Computed tomography coronary angiography (CTCA) has become a commonly used imaging modality in patients with suspected anginal symptoms but also in asymptomatic populations. This practice has raised concerns due to potential high radiation exposure in terms of adequate benefit to risk profile.

DESIGN

Demographics and CTCA scan details were collected from a consecutive series of 586 patients referred to a single community radiology practice for a CTCA.

RESULTS

Of the 586 patients, 271 (46.2%) were women. Mean age was 58.3 standard deviation (SD) 12.2, range 15-90 years, body mass index (BMI) 28.6 SD 5.9 kg/m(2), and heart rate 60 SD 10 beats per minute. Mean total radiation was 4.79 SD 3.45 mSv (range 0.64-31.34). The mean radiation exposure in the lowest quartile of BMI and heart rate were 3.01 SD 1.84 mSv and 3.95 SD 2.72 mSv, compared to the highest 7.32 SD 3.51 mSv and 6.20 SD 4.38 mSv (p for trend <0.0001 in both).

CONCLUSION

The radiation exposure in this consecutive series of patients is low in general but patient selection for CTCA imaging appears to be paramount. Patients with a high BMI and especially with high heart rate receive a higher dose of radiation.

Non-invasive diagnostic testing for coronary artery disease in the hypertensive patient: potential advantages of a risk estimation-based algorithm

Hypertension is a major risk factor for cardiovascular disease, including coronary atherosclerosis and its clinical manifestations. Non-invasive diagnosis of coronary artery disease in hypertension, however, remains a major clinical challenge. Chest pain frequently occurs in hypertensive patients with and without impairment of coronary blood flow supply. Electrocardiographic abnormalities are also common in these patients, thereby leading to further diagnostic difficulty. On the other hand, international guidelines are rather elusive on the recommended diagnostic pathway for coronary artery disease detection in hypertensive patients.In this article, we review the strengths and limitations of current diagnostic methods used to properly identifying coronary artery disease in hypertensive patients. Furthermore, we analyze the usefulness of adopting preliminary and comprehensive cardiovascular risk stratification, together with the evaluation of markers of organ damage, in order to improve the diagnostic efficacy.Despite the high prevalence of arterial hypertension, we still lack a strategy which would lead to validated and cost-effective clinical decision-making processes in hypertensive patients, which help clinicians to minimize useless, ineffective and expensive diagnostic steps. For this purpose, future guidelines should address the issue of diagnostic strategies for an early identification of hypertensive patients at risk of coronary artery disease. This may facilitate appropriate therapeutic choices to optimize the clinical management of coronary disease in hypertension.