ABIM Interventional Cardiology cheat sheet

Physiologic lesion significance: FFR ≤0.80 and iFR ≤0.89 identify lesions warranting revascularization; FFR is measured at maximal hyperemia, iFR at rest over the diastolic wave-free period.

Instantaneous wave-free ratio avoids adenosine but is unreliable in severe left ventricular hypertrophy, tachyarrhythmia, and acute STEMI culprit lesions.

Stent sizing: aim for 1:1 reference vessel diameter with post-dilation to achieve stent expansion; IVUS-defined minimum stent area <5.0 mm² (or <5.5 mm² in left main) predicts restenosis and stent thrombosis.

DAPT after elective PCI: aspirin plus a P2Y12 inhibitor for at least 6 months, then aspirin indefinitely; high bleeding risk may shorten to 1–3 months.

In-stent restenosis mechanisms: neointimal hyperplasia (early, bare-metal era), neoatherosclerosis (late, drug-eluting stents), and stent underexpansion or fracture.

Left main PCI requires intravascular imaging guidance and is preferred over CABG when SYNTAX score is low and surgical risk is prohibitive.

Fractional flow reserve of a non-culprit lesion in acute MI should be deferred until after the acute inflammatory phase resolves, typically 3–7 days.

STEMI reperfusion: primary PCI within 120 minutes of first medical contact is preferred; fibrinolysis if PCI cannot be achieved within 120 minutes and symptom onset is <12 hours.

Door-to-balloon target ≤90 minutes at PCI-capable centers; ≤120 minutes when transfer is required.

High-sensitivity troponin: a single value below the limit of detection with >3 hours of symptoms can rule out MI; serial 0/1-hour algorithms are validated.

Cardiogenic shock in STEMI: early revascularization of the culprit lesion improves survival; routine complete revascularization at the time of index PCI does not.

Antithrombotic therapy in ACS: aspirin plus a P2Y12 inhibitor (ticagrelor or prasugrel preferred over clopidogrel in ACS) plus parenteral anticoagulation.

Right ventricular infarction: suspect with inferior STEMI, hypotension, and clear lungs; treat with volume loading and avoid nitrates and diuretics.

Mechanical complications of STEMI: papillary muscle rupture (acute mitral regurgitation), ventricular septal rupture, and free wall rupture - all carry high mortality and require urgent surgery.

Severe aortic stenosis by echocardiography: aortic valve area <1.0 cm², mean gradient ≥40 mmHg, or peak velocity ≥4.0 m/s; low-flow low-gradient requires dobutamine stress or CT calcium scoring.

TAVR is preferred over surgical AVR in patients ≥80 years or with prohibitive/high surgical risk; shared decision-making applies to intermediate risk.

Paravalvular leak after TAVR: mild or greater is associated with increased mortality; assess with echocardiography and consider balloon post-dilation or a second valve.

Mitral transcatheter edge-to-edge repair (TEER) is indicated for primary degenerative mitral regurgitation in prohibitive surgical risk and for secondary MR with appropriate anatomy and heart failure.

Mitral stenosis: mitral valve area ≤1.5 cm² with symptoms or pulmonary hypertension warrants balloon mitral valvuloplasty if valve morphology is favorable (low Wilkins score).

Left atrial appendage occlusion is an alternative to anticoagulation in nonvalvular atrial fibrillation with contraindication to long-term oral anticoagulation.

Prosthetic valve thrombosis: managed with fibrinolysis or surgery depending on thrombus burden, NYHA class, and valve type; TEE is the diagnostic standard.

Ankle-brachial index ≤0.90 diagnoses peripheral artery disease; values >1.40 suggest noncompressible calcified vessels.

Rutherford and Fontaine classifications grade claudication versus critical limb-threatening ischemia; rest pain, ulceration, or gangrene defines chronic limb-threatening ischemia.

Iliac artery disease: endovascular stenting is first-line for focal lesions; aortoiliac bypass reserved for extensive disease or failed endovascular therapy.

Femoropopliteal disease: drug-coated balloons and drug-eluting stents reduce restenosis versus plain balloon angioplasty; long lesions may need covered stents or bypass.

Deep vein thrombosis: iliofemoral DVT with phlegmasia cerulea dolens warrants catheter-directed thrombolysis or thrombectomy plus anticoagulation.

Post-thrombotic syndrome: chronic venous insufficiency after DVT; managed with compression therapy and venoplasty/stenting of chronic iliac obstruction.

Peripheral intervention anticoagulation: intraprocedural heparin with weight-based dosing; post-procedure antiplatelet therapy depends on stent type and bleeding risk.

Cardiac output by Fick: CO = VO₂ / (CaO₂ − CvO₂); thermodilution is an alternative when no shunt is present.

Cardiac index <2.2 L/min/m² with elevated filling pressures defines cardiogenic shock in the catheterization laboratory.

Transpulmonary gradient = mean pulmonary artery pressure − pulmonary capillary wedge pressure; >12 mmHg suggests pre-capillary pulmonary hypertension.

Pulmonary vascular resistance = (mean PA pressure − PCWP) / cardiac output; normal is <3 Wood units.

Aortic stenosis grading by catheterization: peak-to-peak gradient and calculated valve area using the Gorlin equation; low-output states require dobutamine challenge.

Radial access reduces access-site bleeding and vascular complications versus femoral; use Allen test or barbeau test and ultrasound guidance when feasible.

Femoral access: fluoroscopic landmark at the inferior border of the femoral head; avoid punctures above the inguinal ligament or below the femoral bifurcation.

Unfractionated heparin monitoring: activated clotting time target 250–300 seconds for PCI without glycoprotein IIb/IIIa inhibitor; 200–250 seconds with one.

Bivalirudin: direct thrombin inhibitor with predictable pharmacokinetics; preferred in heparin-induced thrombocytopenia.

P2Y12 inhibitors: clopidogrel is a prodrug requiring CYP2C19 activation; prasugrel and ticagrelor have faster, more potent antiplatelet effects.

Glycoprotein IIb/IIIa inhibitors (abciximab, eptifibatide, tirofiban) are reserved for high thrombus burden or bailout, not routine use.

Contrast-induced acute kidney injury: use iso-osmolar or low-osmolar contrast, minimize volume, and hydrate with isotonic saline; no proven benefit from sodium bicarbonate or N-acetylcysteine.

Cangrelor is an intravenous, reversible P2Y12 inhibitor with rapid onset and offset, useful when oral absorption is unreliable.

Anticoagulation during TAVR or structural procedures: heparin with ACT target typically 250–300 seconds depending on the device.

Contrast-induced nephropathy: defined as a rise in serum creatinine ≥0.3 mg/dL or ≥50% within 48–72 hours of contrast exposure.

Perforation and tamponade: suspect with hypotension, elevated filling pressures, and echocardiographic pericardial effusion; treat with pericardiocentesis and reversal of anticoagulation.

No-reflow phenomenon: impaired myocardial perfusion after PCI despite epicardial patency; treated with intracoronary adenosine, verapamil, or nicardipine.

Radiation safety: ALARA principle; lead apron, thyroid shield, and dosimeter; collimation and reduced frame rate lower dose.

Radiation skin injury threshold: deterministic effects begin around 2 Gy; fluoroscopy time and dose-area product should be tracked for long procedures.

Access-site complications: hematoma, pseudoaneurysm, arteriovenous fistula, and retroperitoneal hemorrhage; retroperitoneal bleed presents with hypotension and back pain.

Coronary air embolism: treat with 100% oxygen, Trendelenburg position, and aspiration through the catheter; supportive care for arrhythmias.

Intravascular ultrasound: provides cross-sectional vessel and plaque imaging; guides stent sizing and detects underexpansion, dissection, and malapposition.

Optical coherence tomography: higher resolution than IVUS (10–20 µm) but limited penetration; useful for plaque characterization and stent strut assessment.

Quantitative coronary angiography: reference diameter, minimum lumen diameter, and percent diameter stenosis derived from edge-detection algorithms.

FFR and iFR are the standard physiologic indices for intermediate lesions; coronary flow reserve and index of microcirculatory resistance assess microvascular function.

CT-derived FFR (FFR-CT) is a noninvasive alternative for intermediate lesions but has lower specificity in heavily calcified vessels.

Intravascular imaging guidance during complex PCI (left main, bifurcation, long lesions) improves outcomes versus angiography alone.

Instantaneous wave-free ratio and FFR discordance occurs in about 15–20% of lesions; repeat measurement or use alternate index when discordant.

Balloon aortic valvuloplasty is a temporizing measure for severe aortic stenosis in patients who are not candidates for TAVR or surgery.

TAVR valve types: balloon-expandable and self-expanding; annular sizing by CT is critical to avoid paravalvular leak and annular rupture.

Bicuspid aortic valve anatomy increases risk of paravalvular leak and annular injury during TAVR; CT sizing and valve selection are essential.

Mitral annular calcification complicates transcatheter mitral intervention; CT assessment of calcium distribution guides device selection.

Patent foramen ovale closure is indicated for cryptogenic stroke in patients <60 years with high-risk PFO features after thorough evaluation.

Atrial septal defect closure: device closure preferred when defect is secundum type with adequate rims and pulmonary vascular resistance is not severely elevated.

Procedural anticoagulation for structural interventions must account for device thrombogenicity and patient bleeding risk; post-procedure DAPT or anticoagulation depends on indication.

Radial artery occlusion: incidence reduced with patent hemostasis technique and adequate anticoagulation; assess with reverse Barbeau test.

Closure devices for femoral access include collagen plug, suture-mediated, and clip-based systems; contraindicated in small vessels, severe calcification, or access above the inguinal ligament.

Radial access spasm: prevented with hydrophilic sheath, intra-arterial vasodilators (nitroglycerin, verapamil), and gentle catheter manipulation.

Femoral artery pseudoaneurysm: diagnosed by duplex ultrasound; treat with ultrasound-guided compression or thrombin injection if conservative measures fail.

Retroperitoneal hemorrhage: suspect with hypotension, flank pain, and dropping hemoglobin after femoral access; CT confirms diagnosis and treatment may require coil embolization or surgery.

Access-site bleeding risk factors: female sex, low body weight, chronic kidney disease, and use of glycoprotein IIb/IIIa inhibitors.

Radial artery harvest for CABG: avoid radial access in patients who may need future radial artery conduit for bypass.