Nonobstructive Versus Obstructive Coronary Artery Disease in Acute Coronary Syndrome: A Meta-Analysis
Carmine Pizzi1, Borejda Xhyheri2, Grazia Maria Costa2
1Department of Specialised, Experimental and Diagnostic Medicine, University of Bologna, Italy carmine.pizzi@unibo.it.
Insights
Patients with nonobstructive coronary artery disease (NObCAD) and acute coronary syndrome have a lower risk of major cardiovascular events than those with obstructive disease (ObCAD). However, NObCAD patients still face significant risks, indicating a need for tailored management strategies.
Area of Science:
- Cardiology
- Clinical Research
- Epidemiology
Background:
- Acute coronary syndrome (ACS) patients present with either obstructive coronary artery disease (ObCAD) or nonobstructive coronary artery disease (NObCAD).
- Previous studies show varied event rates between ObCAD and NObCAD, necessitating a comprehensive analysis.
Purpose of the Study:
- To compare the clinical presentation and prognosis of ACS patients with NObCAD versus ObCAD.
- To evaluate event rates in patients with zero versus mild coronary artery occlusion.
Main Methods:
- A systematic meta-analysis was conducted using data from MedLine, EMBASE, and Cochrane databases up to June 2015.
- Random-effect meta-analyses compared event risks between NObCAD and ObCAD groups.
- Yearly and monthly outcome rates were estimated for each group.
Main Results:
- NObCAD patients had significantly lower rates of all-cause mortality, myocardial infarction, cardiac death, and major cardiovascular events compared to ObCAD patients.
- Risk ratios for these outcomes ranged from 0.33 to 0.66 in favor of NObCAD.
- No significant differences in outcome rates were found between patients with mild (1-49% stenosis) and zero coronary artery occlusion.
Conclusions:
- ACS patients with NObCAD exhibit lower baseline cardiovascular risk and reduced likelihood of death or major adverse events compared to ObCAD patients.
- Despite lower risks, NObCAD patients remain at high risk for cardiovascular mortality and morbidity.
- These findings suggest potential undertreatment in NObCAD patients and highlight the need for specific management guidelines.
Background:
Differences in prognosis and baseline clinical presentation have been documented among patient with acute coronary syndrome and coronary artery disease with obstructive (ObCAD) or nonobstructive arteries (NObCAD), but the rates of events largely varied across single studies. We carried out a meta-analysis to compare the clinical presentation and prognosis of NObCAD versus ObCAD acute coronary syndrome patients, as well as of the subjects with zero versus mild occlusion.
Methods And Results:
Searches were made in MedLine, EMBASE, Cochrane databases, and proceedings of international meetings up to June 30, 2015. We compared the risk of events of NObCAD versus ObCAD patients using random-effect meta-analyses. We also performed meta-analyses to estimate the yearly or monthly outcome rates in each single group. In NObCAD and ObCAD patients, respectively, the combined yearly rates were as follows: 2.4% versus 10.1% (all-cause mortality); 1.2% versus 6.0% (myocardial infarction), 4.0% versus 12.8% (all-cause mortality plus myocardial infarction), 1.4% versus 5.9% (cardiac death), and 9.2% versus 16.8% (major cardiovascular events). In the studies directly comparing NObCAD versus ObCAD, all of the above outcomes were significantly less frequent in NObCAD subjects (with risk ratios ranging from 0.33 to 0.66). No differences in any outcome rate were observed between mild occlusion (1-49% stenosis) and zero occlusion patients.
Conclusions:
NObCAD in patients with acute coronary syndrome has a significantly lower cardiovascular risk at baseline and a subsequent lower likelihood of death or main cardiovascular events. However, these subjects are still at high risk for cardiovascular mortality and morbidity, suggesting potential undertreatment and calling for specific management.
