Presentation, care and outcomes of patients with NSTEMI according to World Bank country income classification: Prospective international multicentre cohort study of the ESC EORP NSTEMI registry
Authors: Nadarajah R , Ludman P , Appelman Y , Brugaletta S , Budaj A , Bueno H , Huber K , Kunadian V , Leonardi S , Lettino M , Milasinovic D , Gale C P 
Published: May 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
The majority of NSTEMI burden resides outside high income countries (HICs). Care that conforms to the European Society of Cardiology (ESC) guidelines has been demonstrated to improve outcomes,2-6 but places a financial burden on healthcare systems.7 Whether care quality and outcomes vary by country economic prosperity is unknown. The EURObservational Research Programme (EORP) NSTEMI registry was designed and implemented to identify patterns in NSTEMI care and outcomes across the heterogeneous context of ESC country members and affiliated countries.

Purpose
We describe presentation, care and outcomes of NSTEMI by World Bank country income classification.

Methods
Prospective cohort study (11 March 2019 to 6 March 2021) including 2947 adult patients with NSTEMI from 287 centres in 59 countries. For each patient demographic features, therapeutic methods, treatment delays, risk stratification and medication prescription during admission and on discharge were recorded. Quality of care was evaluated based on 12 guideline-recommended care interventions. The all-or-none scoring composite performance measure was used to define receipt of optimal care. Outcomes included in-hospital repeat myocardial infarction, acute heart failure and death, and 30-day mortality.

Results
Patients admitted with NSTEMI in low-lower middle income countries (LLMICs), compared to patients in HICs, were younger (median age 58 years [IQR 51-65] vs 68 [59-77]), more commonly diabetic (48.6% vs 34.2%) but with a lower burden of other comorbidities (Table 1). Of patients with NSTEMI in LLMICs, 76.7% met very high risk criteria for an immediate invasive strategy. Compared to patients in HICs, the proportion of patients in LLMICs presenting in Killip Class III or IV was three-fold higher; and ongoing chest pain, life-threatening arrhythmias, and hemodynamic instability were at least twice as common. Invasive coronary angiography use increased with ascending income classification (LLMICs, 79.2%; upper middle income countries [UMICs], 83.7%; HICs, 91.0%), but overall care quality did not (≥80% of eligible interventions achieved: LLMICS, 64.8%; UMICs 69.6%; HICs 55.1%) (Figure 1). Rates of acute heart failure (LLMICS, 21.3%; UMICs, 12.1%; 3.2%; HICs, 6.8%; p&lt;0.001), repeat myocardial infarction (LLMICS: 2.5%; UMICs: 1.5%; HICs: 0.9%; p=0.04), in-hospital mortality (LLMICS, 3.6%; UMICs: 2.8%; HICs: 1.0%; p&lt;0.001) and 30 day mortality (LLMICs, 4.9 %; UMICs, 3.9%; HICs, 1.5%; p&lt;0.001) exhibited an inverse economic gradient.

Conclusions
Patients with NSTEMI in LLMICs present at a younger age, with fewer comorbidities, at a more advanced stage of acute disease, and have worse outcomes compared with HICs. Overall care did not vary by income classification, but there was a shortfall in provision of interventional procedures in LLMICs. A cardiovascular health narrative is needed to address this inequity across economic boundaries.