Is zero contrast angioplasty (angioplasty without contrast media) possible in patients with Acute Coronary Syndrome (ACS)?

Zero Contrast Angioplasty in Acute Coronary Syndrome

Zero contrast angioplasty is possible in selected patients with Acute Coronary Syndrome (ACS), particularly those at high risk for contrast-induced acute kidney injury (CI-AKI), but should be limited to specialized centers with appropriate expertise and technology. 1

Indications for Zero Contrast Approach

• Zero contrast angioplasty should be considered in ACS patients with severe chronic kidney disease (CKD), as these patients are at highest risk for contrast-induced nephropathy 1
• Patients with cardiogenic shock complicating ACS who also have significant renal dysfunction may be candidates for this approach, as they require emergency coronary intervention but are particularly vulnerable to CI-AKI 1
• Patients with diabetes mellitus and concomitant CKD represent another high-risk group where zero contrast techniques may be beneficial 1

Technical Considerations

• Radial access is recommended as the standard approach for coronary interventions in ACS patients, which is particularly important when attempting zero contrast techniques to reduce vascular complications 1
• Intravascular ultrasound (IVUS) or optical coherence tomography (OCT) guidance is essential for zero contrast PCI to provide vessel sizing and lesion assessment 1
• Drug-eluting stents (DES) are recommended over bare-metal stents for any PCI in ACS patients, including zero contrast procedures 1
• The procedure should focus on the culprit lesion only in ACS patients, particularly those with cardiogenic shock, as routine immediate revascularization of non-culprit lesions is not recommended 1

Patient Selection and Risk Assessment

• Assessment of contrast-induced AKI risk should be performed before any procedure in patients with suspected ACS 1
• Estimated glomerular filtration rate (eGFR) should be calculated in all ACS patients to identify those with renal impairment who might benefit from zero contrast techniques 1
• For patients with intermediate or high GRACE risk scores (>109) requiring invasive management, zero contrast techniques should be considered if they have significant renal dysfunction 1

Limitations and Challenges

• Zero contrast PCI requires specialized expertise and may not be available at all centers treating ACS patients 1
• The approach is technically more challenging and may be limited to relatively straightforward lesions 1
• In patients with cardiogenic shock or very high-risk features requiring immediate intervention, the mortality benefit of revascularization likely outweighs the risk of CI-AKI, and minimal contrast use may be preferable to zero contrast if it enables more complete revascularization 1

Alternative Approaches to Minimize Contrast Exposure

• When zero contrast is not feasible, minimizing contrast volume remains a key strategy 1
• Use of low- or iso-osmolar contrast media at the lowest possible volume is recommended in patients with renal impairment 1
• Adequate preprocedural hydration is essential for patients at risk of CI-AKI 1
• High-dose statin pretreatment before diagnostic catheterization has been shown to reduce the occurrence of contrast-induced AKI 1

Special Considerations in ACS

• In patients with NSTE-ACS requiring an immediate invasive strategy (<2h), such as those with hemodynamic instability or cardiogenic shock, the benefit of timely revascularization generally outweighs the risk of contrast exposure 1
• For ACS patients with multivessel disease and renal dysfunction, a staged approach may be preferable, with zero contrast PCI of the culprit lesion followed by subsequent reassessment for treatment of other lesions 1
• Emergency echocardiography should be performed in ACS patients with heart failure or suspected mechanical complications to guide management decisions before considering zero contrast angioplasty 1

Zero contrast angioplasty represents an important technical advancement for managing high-risk ACS patients with significant renal dysfunction, but requires specialized expertise and should be part of a comprehensive strategy to reduce contrast-induced nephropathy risk.