High-Risk & Complex Angioplasty

IVL uses pulsatile sonic pressure waves — the same physics as kidney stone lithotripsy — delivered from inside the coronary artery to fracture both superficial and deep calcium deposits without damaging the vessel wall or surrounding tissue. A specialised balloon catheter containing miniature lithotripters is positioned at the calcified segment. Each pulse generates a focused shockwave that cracks the calcium circumferentially, dramatically softening the artery and enabling optimal stent expansion at low balloon pressures. IVL has transformed the treatment of severely calcified coronary disease — lesions that previously required rotational atherectomy or were referred for bypass surgery can now be treated safely and predictably.

Rotational atherectomy uses a high-speed (140,000–180,000 rpm) diamond-coated burr advanced over a coronary guidewire to ablate calcified plaque. The differentially cutting mechanism ablates hard calcified tissue while deflecting the softer, elastic normal vessel wall — converting calcium into microparticles smaller than 10 µm that are safely cleared by the reticuloendothelial system. Rotablation changes vessel compliance — converting a rigid, calcified tube into a more distensible segment that accepts a stent. It is particularly used for lesions with concentric calcium that prevents adequate pre-dilation or stent delivery.

Bifurcation lesions — blockages at arterial branch points — occur in approximately 15–20% of all PCI cases and carry higher procedural complication rates and restenosis risk than non-bifurcation disease. The challenge is maintaining flow in both the main vessel and the side branch simultaneously. A provisional one-stent strategy (treating the main vessel first, with selective side-branch stenting only if needed) is preferred for most bifurcations. For complex true bifurcations involving a large side branch, a two-stent technique — DK-Crush (demonstrated superior in the DKCRUSH-V trial) or Culotte — is employed. OCT guidance is used to confirm optimal stent apposition and detect side-branch jailing after kissing balloon inflation.

The left main coronary artery — which supplies 70–80% of the left ventricular myocardium — was historically treated exclusively by bypass surgery. The EXCEL (2016) and NOBLE (2016) randomised trials established left main PCI as a guideline-supported alternative to CABG in patients with low-to-intermediate SYNTAX scores, with 5-year outcomes comparable to surgery. IVUS guidance is mandatory for left main PCI — the true vessel diameter (frequently 4–5 mm) is consistently underestimated by angiography alone, and stent underexpansion in the left main is the most common cause of failure. Post-stent OCT or IVUS confirmation of full expansion, complete apposition, and absence of edge dissection is performed in every case. All left main PCI cases at Heartwise Cardiology are discussed in a cardiac surgical team context before proceeding.

A Chronic Total Occlusion (CTO) is a coronary artery that has been completely blocked (100% stenosis) for more than 3 months. CTO PCI is the most technically challenging procedure in interventional cardiology — it uses specialised antegrade and retrograde wire crossing techniques, dedicated CTO guidewires, and microcatheters to navigate through the occluded segment and restore blood flow. In experienced, high-volume CTO operators, procedural success rates exceed 85–90%. Successful CTO PCI relieves angina, reduces ischaemia, and in patients with viable but hibernating myocardium, may improve left ventricular function.

In patients with blockages in two or three coronary arteries simultaneously, a critical decision must be made: treat all lesions, or only the most functionally significant ones? Treating anatomically significant but haemodynamically non-significant stenoses adds procedural risk, stent material, and DAPT duration without clinical benefit. The FAME 2 trial established that FFR-guided PCI — treating only stenoses with FFR ≤ 0.80 — is superior to both angiography-guided PCI and medical therapy alone for haemodynamically significant lesions. In multi-vessel disease, FFR guidance determines which lesions truly require stenting, resulting in fewer stents, shorter DAPT duration, and equivalent or better clinical outcomes than treating all anatomical stenoses. A staged approach — treating the culprit vessel first, then returning for other significant vessels in a separate session 2–6 weeks later — is generally preferred over single-session multi-vessel PCI.