Clinical outcomes of patients discharged from the Rapid Access Chest Pain Clinic with non-anginal chest pain: A retrospective cohort study.

BACKGROUND: The Rapid Access Chest Pain Clinic (RACPC) has become an important means of assessing patients who present with ischaemic or ischaemia-like symptoms of recent onset. Observations have shown that up to 70% are discharged with a diagnosis of non-anginal chest pain (NACP) and accordingly "reassured". This study aims to describe the actual clinical outcomes of this cohort of patients discharged from the RACPC. METHODS: We undertook a single centre retrospective cohort study at a tertiary cardiac hospital. The outcomes of unselected patients diagnosed with NACP and discharged from the RACPC between April 2010 and March 2013 at University Hospitals of Leicester (UHL) were recorded. Re-referrals to cardiology outpatient clinic and emergency hospital admissions for cardiovascular disease within 6 months, and the mortality rate at 12 months, were determined. RESULTS: 7066 patients were seen in the UHL RACPC during the 36-month period. 3253 (46.0%) were diagnosed with NACP and discharged. 7 (0.2%) were diagnosed with coronary artery disease (CAD) and 8 (0.25%) cases of acute coronary syndrome (ACS) identified during the review period. 11 (0.3%) patients died within 12 months of discharge from RACPC. No deaths were attributable to CAD. CONCLUSIONS: Comprehensive assessment using risk-stratification criteria in a nurse practitioner-led RACPC can accurately identify patients who are at low-risk for subsequent CAD. Despite contemporary National Institute for Health and Care Excellence (NICE) guidelines that shift focus away from a clinical judgement based approach, this strategy appears to robustly predict favourable outcomes in patients diagnosed with NACP.

Bladder and cutaneous sensory neurons of the rat express different functional P2X receptors.

The expression and functional responses of P2X receptors in bladder and cutaneous sensory neurons of adult rats and mice have been studied using immunohistochemistry and patch clamp techniques. Cell bodies of bladder pelvic afferents were identified in L6 and S1 dorsal root ganglia (DRG), following Fast Blue injection into the muscle wall of the urinary bladder. Similarly, cutaneous sensory neurons were identified in L3 and L4 DRG, following Fast Blue injection into the saphenous nerve innervating the skin. Bladder sensory neurons contained only weak to moderate P2X(3)-immunoreactivity (IR), in contrast to strong P2X(3)-IR observed in a sub-population of cutaneous afferents. Whole-cell patch-clamp recordings revealed that approximately 90% of bladder afferent neurons responded to alpha beta-methylene ATP (alpha beta meATP) and ATP (30 microM) with persistent currents, which were inhibited by 2',3'-O-trinitrophenyl-ATP (TNP-ATP) (0.3 microM) to 6.4+/-1.9% and 8.0+/-2.6% of control, respectively (n=8). The remaining bladder sensory neurons demonstrated biphasic, transient or no response to P2X agonists. In contrast, only 24% of cutaneous afferent neurons gave persistent currents to alpha beta meATP (30 microM), with 66% of cells giving transient or biphasic currents and the remaining 10% being non-responsive. Our results suggest that, in contrast to DRG neurons in general, bladder sensory neurons projecting via pelvic nerves express predominantly P2X(2/3) heteromeric receptors, which are likely to mediate the important roles of ATP as a signaling molecule of urinary bladder filling and nociception.