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The Council of the Canadian Cardiovascular Society commissioned working groups to examine issues of access to, and wait times for, various aspects of cardiovascular care. The present article summarizes the deliberations on targets for medically acceptable wait times for access to cardiovascular specialist evaluation and on the performance of noninvasive testing needed to complete this evaluation. Three categories of referral indications were identified: those requiring hospitalization due to substantial ongoing risk of mortality and morbidity; those requiring an expedited early review in an ambulatory setting; and, finally, a larger category in which delays of two to six weeks can be justified. The proposed wait time targets will provide guidance on the timeliness of care to busy clinicians charged with the care of patients with cardiovascular disease, help policy makers appreciate the clinical challenges in providing access to high quality care, and highlight the critical need for a thoughtful review of cardiology human resource requirements. Wait time implementation suggestions are also included, such as the innovative use of disease management and special need clinics. The times proposed assume that available clinical practice guidelines are followed for clinical coronary syndrome management and for treatment of associated conditions such as hypertension, diabetes, renal disease, smoking cessation and lipid disorders. Although media attention tends to focus on wait times for higher profile surgical procedures and high technology imaging, it is likely that patients face the greatest wait-related risk at the earlier phases of care, before the disease has been adequately characterized.

Background: Impairment of myocardial flow reserve (MFR) in aortic stenosis (AS) with normal left ventricular function relates to the haemodynamic severity. Objectives: To investigate whether myocardial blood flow (MBF) and MFR differ in low-flow, low-gradient AS depending on whether there is underlying true-severe AS (TSAS) or pseudo-severe AS (PSAS). Methods: In 36 patients with low-flow, low-gradient AS, dynamic [13N]ammonia PET perfusion imaging was performed at rest (n = 36) and during dipyridamole stress (n = 20) to quantify MBF and MFR. Dobutamine echocardiography was used to classify patients as TSAS (n = 181 or PSAS (n = 18) based on the indexed projected effective orifice area (EOA) at a normal flow rate of 250 ml/s (EOAlproj ⩽ or >0.55 cm2/m2). Results: Compared with healthy controls )n = 14), patients with low-flow, low-gradient AS had higher resting mean (SD) MBF (0.83 (0.21) vs 0.69 (0.09) ml/min/g, p = 0.001), reduced hyperaemic MBF (1.16 (0.31) vs 2.71 (0.50) ml/min/g, p<0.001) and impaired MFR (1.44 10.44) vs 4.00 (0.91), p<0.00l). Resting MBF and MFR correlated with indices of AS severity in low- flow, low-gradient AS with the strongest relationship observed for EOAlproj (rs = -0.50, p = 0.002 and = 0.61, p = 0.004, respectively). Compared with PSAS, TSAS had a trend to a higher resting MBF (0.90 (0.19) vs 0.77 (0.21) ml/min/g, p = 0.06), similar hyperaemic MBF (1.16 (0.31) vs 1.17 (0.32) ml/min/g, p = NS), but a significantly smaller MFR (1.19 (0.26) vs 1.76 (0.41), p = 0.003). An MFR <1.8 had an accuracy of 85% for distinguishing TSAS from PSAS. Conclusions: Low-flow, low-gradient AS is characterised by higher resting MBF and reduced MER that relates to the AS severity. The degree of MFR impairment differs between TSAS and PSAS and may be of value for distinguishing these entities. [ABSTRACT FROM AUTHOR]