What is the role of PTCA (Percutaneous Transluminal Coronary Angioplasty) with ROTA (Rotational Atherectomy) and EBUS (Endobronchial Ultrasound) in cardiology?

Role of PTCA with Rotational Atherectomy and EBUS in Cardiology

Rotational atherectomy is useful for fibrotic or heavily calcified coronary lesions that cannot be crossed by a balloon catheter or adequately dilated before stent implantation, while EBUS has no established role in coronary interventions. 1

Rotational Atherectomy (ROTA) in PTCA

Mechanism and Indications

Rotational atherectomy uses a diamond-tipped burr that rotates at high speeds (140,000-180,000 rpm) to excavate inelastic atherosclerotic tissue. It functions by:

• Pulverizing atherosclerotic plaque, particularly calcified material
• Facilitating stent delivery in heavily calcified vessels
• Improving stent expansion in fibrotic lesions

The 2021 ACC/AHA/SCAI Guideline for Coronary Artery Revascularization provides a Class IIa recommendation (Level of Evidence: B-R) for rotational atherectomy in patients with fibrotic or heavily calcified lesions 1.

Clinical Applications

Rotational atherectomy should be used selectively for:

1. Lesions that cannot be crossed with a balloon catheter
2. Lesions that cannot be adequately dilated with conventional balloons
3. Heavily calcified lesions where stent delivery would otherwise be impossible
4. Situations where optimal stent expansion is hindered by calcification

Limitations and Cautions

Despite its utility in specific situations, rotational atherectomy has important limitations:

• Should NOT be performed routinely for de novo lesions or in-stent restenosis 1
• Associated with increased rates of restenosis and late lumen loss in older studies 1
• Can lead to complications including coronary spasm and no/slow-flow phenomenon 1
• Does not improve long-term clinical or angiographic outcomes compared to standard PCI 1

The ARTIST trial demonstrated that for in-stent restenosis, balloon angioplasty alone produced significantly better long-term outcomes than rotational atherectomy followed by low-pressure PTCA 2.

Other Plaque Modification Techniques

The 2021 ACC/AHA/SCAI guidelines also mention alternative plaque modification techniques (Class IIb, Level of Evidence: B-NR) 1:

• Orbital atherectomy
• Balloon atherotomy (cutting balloon)
• Laser angioplasty
• Intracoronary lithotripsy

Cutting balloon angioplasty might be considered to avoid slippage-induced coronary artery trauma during PCI for in-stent restenosis or ostial lesions in side branches, but should not be performed routinely 1.

Special Populations Benefiting from ROTA

Certain patient populations may particularly benefit from rotational atherectomy:

• Hemodialysis patients with heavily calcified lesions 3, 4
• Patients with unprotected left main disease with severe calcification 4
• Patients with ostial and branch-ostial lesions 5

A study of hemodialysis patients with calcified coronary lesions showed lower rates of target lesion revascularization when rotational atherectomy was used before drug-eluting stent implantation (11.5% vs 35.7%, p=0.026) 3.

EBUS (Endobronchial Ultrasound) in Cardiology

EBUS is primarily a pulmonary diagnostic tool and has no established role in coronary interventions. The guidelines do not mention EBUS for coronary procedures 1.

For intravascular imaging during coronary procedures, the established modalities are:

1. Intravascular Ultrasound (IVUS)

   • Useful for assessing left main coronary artery disease (Class IIa, Level of Evidence: B) 1
   • Helps identify stent underexpansion or malapposition 1
   • Superior to angiography for detecting cardiac allograft vasculopathy 1

2. Optical Coherence Tomography (OCT)

   • Higher resolution than IVUS (10-20 micrometers axially)
   • Limited depth of imaging (1-1.5 mm)
   • Requires artery perfusion with saline during image acquisition 1

Practical Algorithm for Using Rotational Atherectomy

1. Assessment phase:

   • Identify heavily calcified lesions (calcium deposits >500 mm thick or involving >270° arc on intravascular imaging)
   • Attempt conventional balloon angioplasty first

2. Decision point:

   • If unable to cross lesion with balloon OR
   • If unable to adequately dilate lesion with high-pressure balloon

3. Implement rotational atherectomy:

   • Use stepped-burr approach (start with smaller burr size)
   • Follow with adjunctive balloon angioplasty
   • Complete with stent implantation (preferably drug-eluting stent)

4. Post-procedure assessment:

   • Verify adequate stent expansion with intravascular imaging when possible
   • Monitor for complications including no-reflow phenomenon

Remember that while rotational atherectomy can facilitate procedural success in specific circumstances, it does not improve long-term clinical outcomes when used routinely and should be reserved for cases where conventional approaches are inadequate.