ABSTRACT
AIMS: CT calcium scoring (CTCS) and CT cardiac angiography (CTCA) are widely used in patients with stable chest pain to exclude significant coronary artery disease (CAD). We aimed to resolve uncertainty about the prevalence of obstructive coronary artery disease and long-term outcomes in patients with a zero-calcium score (ZCS). METHODS AND RESULTS: Consecutive patients with stable cardiac symptoms referred for CTCS or CTCS and CTCA from chest pain clinics to a tertiary cardiothoracic centre were prospectively enrolled. In those with a ZCS, the prevalence of obstructive CAD on CTCA was determined. A follow-up for all-cause mortality was obtained from the NHS tracer service. A total of 3914 patients underwent CTCS of whom 2730 (69.7%) also had a CTCA. Half of the patients were men (50.3%) with a mean age of 56.9 years. Among patients who had both procedures, a ZCS was present in 52.2%, with a negative predictive value of 99.5% for excluding ≥70% stenosis on CTCA. During a mean follow-up of 5.2 years, the annual event rate was 0.3% for those with ZCS compared with 1.2% for CS ≥1. The presence of non-calcified atheroma on CTCA in patients with ZCS did not affect the prognostic value (P = 0.98). CONCLUSION: In patients with stable symptoms and a ZCS, obstructive CAD is rare, and prognosis over the long-term is excellent, regardless of whether non-calcified atheroma is identified. A ZCS could reliably be used as a 'gatekeeper' in this patient cohort, obviating the need for further more expensive tests.
Subject(s)
Angina, Stable/diagnostic imaging , Angina, Stable/epidemiology , Calcinosis/diagnostic imaging , Computed Tomography Angiography , Coronary Artery Disease/diagnostic imaging , Coronary Artery Disease/epidemiology , Aged , Calcinosis/epidemiology , Coronary Angiography/methods , Female , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Multivariate Analysis , Predictive Value of Tests , Prognosis , Risk Assessment , Severity of Illness Index , Survival RateABSTRACT
BACKGROUND: Elective percutaneous coronary intervention (PCI) without inducible ischaemia may not be beneficial. We investigated the prevalence of inducible hypoperfusion using myocardial perfusion scintigraphy (MPS) in patients undergoing PCI, and its ability to predict functional outcome. METHODS AND RESULTS: One hundred and twenty-three patients listed for elective PCI underwent MPS, using treadmill exercise where possible. Seventy-seven patients (63%) described chest pain in daily life. Seventy-four of 103 (72%) exercise ECG tests were positive. Ninety-one (74%) had inducible hypoperfusion on MPS (extensive in 25; 20%). Interventionalists were blinded to the scintigraphic results, and PCI was performed as planned. Six months later, Seattle Angina Questionnaire physical limitation score had improved from 66 to 76 (P < 0.0001), and peak treadmill workload from 7.2 +/- 2.3 to 9.0 +/- 2.7 METS (P < 0.0001). Sex, limiting chest pain on baseline exercise testing, and MPS summed difference score (SDS) were independent predictors of improvement. Patients with both limiting chest pain and SDS > or = 7 demonstrated an increase of 3.3 +/- 1.8 METS, compared with approximately 1.5 METS for other subgroups (P < 0.05). CONCLUSIONS: Many patients undergoing elective PCI in a UK centre have little or no evidence of inducible hypoperfusion. The combination of limiting chest pain during exercise testing and significant inducible hypoperfusion on MPS predicts a large increase in exercise capacity after PCI.
