PET Myocardial Perfusion Imaging: Trends, Challenges, and Opportunities.

Various non-invasive images are used in clinical practice for the diagnosis and prognostication of chronic coronary syndromes. Notably, quantitative myocardial perfusion imaging (MPI) through positron emission tomography (PET) has seen significant technical advancements and a substantial increase in its use over the past two decades. This progress has generated an unprecedented wealth of clinical information, which, when properly applied, can diagnose and fine-tune the management of patients with different types of ischemic syndromes. This state-of-art review focuses on quantitative PET MPI, its integration into clinical practice, and how it holds up at the eyes of modern cardiac imaging and revascularization clinical trials, along with future perspectives.

Validation of resting full-cycle ratio and diastolic pressure ratio with [15O]H2O positron emission tomography myocardial perfusion.

Fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) are invasive techniques used to evaluate the hemodynamic significance of coronary artery stenosis. These methods have been validated through perfusion imaging and clinical trials. New invasive pressure ratios that do not require hyperemia have recently emerged, and it is essential to confirm their diagnostic efficacy. The aim of this study was to validate the resting full-cycle ratio (RFR) and the diastolic pressure ratio (dPR), against [15O]H2O positron emission tomography (PET) imaging. A total of 129 symptomatic patients with an intermediate risk of coronary artery disease (CAD) were included. All patients underwent cardiac [15O]H2O PET with quantitative assessment of resting and hyperemic myocardial perfusion. Within a 2 week period, coronary angiography was performed. Intracoronary pressure measurements were obtained in 320 vessels and RFR, dPR, and FFR were computed. PET derived regional hyperemic myocardial blood flow (hMBF) and myocardial perfusion reserve (MPR) served as reference standards. In coronary arteries with stenoses (43%, 136 of 320), the overall diagnostic accuracies of RFR, dPR, and FFR did not differ when PET hyperemic MBF < 2.3 ml min-1 (69.9%, 70.6%, and 77.1%, respectively) and PET MPR < 2.5 (70.6%, 71.3%, and 66.9%, respectively) were considered as the reference for myocardial ischemia. Non-significant differences between the areas under the receiver operating characteristic (ROC) curve were found between the different indices. Furthermore, the integration of FFR with RFR (or dPR) does not enhance the diagnostic information already achieved by FFR in the characterization of ischemia via PET perfusion. In conclusion, the novel non-hyperemic pressure ratios, RFR and dPR, have a diagnostic performance comparable to FFR in assessing regional myocardial ischemia. These findings suggest that RFR and dPR may be considered as an FFR alternative for invasively guiding revascularization treatment in symptomatic patients with CAD.

Migraine and cardiovascular disease: what cardiologists should know.

Migraine is a chronic neurovascular disease with a complex, not fully understood pathophysiology with multiple causes. People with migraine suffer from recurrent moderate to severe headache attacks varying from 4 to 72 h. The prevalence of migraine is two to three times higher in women compared with men. Importantly, it is the most disabling disease in women <50 years of age due to a high number of years lived with disability, resulting in a very high global socioeconomic burden. Robust evidence exists on the association between migraine with aura and increased incidence of cardiovascular disease (CVD), in particular ischaemic stroke. People with migraine with aura have an increased risk of atrial fibrillation, myocardial infarction, and cardiovascular death compared with those without migraine. Ongoing studies investigate the relation between migraine and angina with non-obstructive coronary arteries and migraine patients with patent foramen ovale. Medication for the treatment of migraine can be preventative medication, such as beta-blockers, angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, antiepileptics, antidepressants, some of the long-acting calcitonin gene-related peptide receptor antagonists, or monoclonal antibodies against calcitonin gene-related peptide or its receptor, or acute medication, such as triptans and calcitonin gene-related peptide receptor antagonists. However, these medications might raise concerns when migraine patients also have CVD due to possible (coronary) side effects. Specifically, knowledge gaps remain for the contraindication to newer treatments for migraine. All cardiologists will encounter patients with CVD and migraine. This state-of-the-art review will outline the basic pathophysiology of migraine and the associations between migraine and CVD, discuss current therapies, and propose future directions for research.

Diagnostic accuracy of non-invasive cardiac imaging modalities in patients with a history of coronary artery disease: a meta-analysis.

BACKGROUND: The diagnostic performance of non-invasive imaging techniques for detecting obstructive coronary artery disease (CAD) in patients with a history of myocardial infarction or percutaneous coronary intervention has not been comprehensively evaluated. This meta-analysis assesses the diagnostic value of coronary CT angiography (CCTA), CCTA combined with CT perfusion (CCTA+CTP), cardiac MRI (CMR) and single-photon emission CT (SPECT) compared with invasive reference standards. METHODS: We systematically searched PubMed, Embase, Web of Science and the Cochrane Library from 2005 to September 2022 for prospective, blinded studies including populations with ≥50% prior CAD. RESULTS: We identified 18 studies encompassing 3265 patients, with obstructive CAD present in 64%. The per-patient sensitivity of CCTA (0.95; 95% CI 0.92 to 0.98), CCTA+CTP (0.93; 95% CI 0.84 to 0.98) and CMR (0.91; 95% CI 0.86 to 0.94) was high, while SPECT showed lower sensitivity (0.63; 95% CI 0.52 to 0.73). SPECT had higher specificity compared with CCTA (0.66; 95% CI 0.56 to 0.76 vs 0.37; 95% CI 0.29 to 0.46), but was comparable to CCTA+CTP (0.59; 95% CI 0.49 to 0.69) and CMR (0.69; 95% CI 0.53 to 0.81). The area under the curve for SPECT was the lowest (0.70; 95% CI 0.58 to 0.87), while CCTA (0.91; 95% CI 0.86 to 0.98), CCTA+CTP (0.89; 95% CI 0.73 to 1.00) and CMR (0.91; 95% CI 0.80 to 1.00) showed similar high values. CONCLUSIONS: In patients with prior CAD, CCTA, CCTA+CTP and CMR demonstrated high diagnostic performance, whereas SPECT had lower sensitivity. These findings can guide the selection of non-invasive imaging techniques in this high-risk population. PROSPERO REGISTRATION NUMBER: CRD42022322348.