Coronary Artery Angiography (CAG) in India and UAE | Complete Patient Guide

• ELIGIBILITY — CLINICAL INDICATIONS:

• Stable angina pectoris with objective evidence of ischemia on non-invasive testing (stress ECG, stress echo, nuclear perfusion imaging, or cardiac MRI)

• Acute Coronary Syndrome (ACS): Non-ST-elevation myocardial infarction (NSTEMI) with intermediate-to-high GRACE score, or ST-elevation myocardial infarction (STEMI) requiring primary PCI

• Suspected left main or multivessel disease with a high pre-test probability of significant CAD

• Pre-operative cardiac evaluation before major non-cardiac surgery in patients with known or high-risk CAD

• Unexplained heart failure or new-onset left ventricular systolic dysfunction (EF < 40%) with possible ischemic etiology

• Valvular heart disease requiring surgical correction in patients aged > 40 years or with cardiac risk factors (to exclude concomitant significant CAD before surgery)

• Positive or equivocal cardiac CT angiography (CCTA) findings requiring anatomical confirmation and possible intervention

• Survivors of sudden cardiac arrest without obvious non-ischemic cause

• Coronary anomalies detected on CCTA requiring functional characterization

• REQUIRED PRE-PROCEDURE DIAGNOSTICS:

• Resting 12-lead ECG and 24–72-hour Holter monitor (where indicated)

• 2D Transthoracic Echocardiography (2D-TTE/ECHO): Assessment of LV/RV function, wall motion abnormalities, valve morphology, and pericardial effusion

• Serum cardiac biomarkers: High-sensitivity Troponin I or T (hs-cTnI/T), CK-MB, BNP/NT-proBNP

• Complete Blood Count (CBC), Renal Function Tests (serum creatinine, eGFR — mandatory for contrast safety), Liver Function Tests, Coagulation profile (PT/INR, aPTT)

• Fasting blood glucose and HbA1c (contrast risk and medication management)

• Lipid panel (LDL-C, HDL-C, triglycerides)

• Thyroid Function Tests (if iodinated contrast allergy protocol or amiodarone use)

• Chest X-ray (PA view)

• Non-invasive stress testing results (stress ECG, nuclear SPECT, stress echo, or cardiac MRI) if available

• Cardiac CT Angiography (CCTA) report, if previously performed

• Blood group and type-and-screen

• CONTRAINDICATIONS (RELATIVE AND ABSOLUTE):

• Severe uncorrected coagulopathy (INR > 2.5 without reversibility strategy) — relative; bridging anticoagulation may be required

• Acute kidney injury or severe chronic kidney disease (eGFR < 30 mL/min/1.73 m²) — relative; require pre-hydration, nephroprotective protocols, and CO₂ angiography or ultra-low contrast volume techniques

• Documented severe allergy to iodinated contrast media without adequate premedication (corticosteroid + antihistamine protocol) — relative

• Uncontrolled severe hypertension (SBP > 200 mmHg) — relative; defer until hemodynamically stabilized

• Decompensated congestive heart failure (hemodynamic instability) — relative; stabilize before elective CAG

• Active systemic infection or sepsis — relative; treat infection first unless ACS mandates urgent CAG

• Severe peripheral arterial disease precluding safe arterial access — alternative access sites (e.g., brachial, ulnar, or distal radial) may be used

• Patient refusal of informed consent — absolute

• Pregnancy: relative contraindication due to radiation exposure; urgent cases require lead shielding and risk-benefit assessment

STANDARD DIAGNOSTIC CORONARY ANGIOGRAPHY (CONVENTIONAL CAG):

The foundational technique involves selective catheterization of the left and right coronary ostia via either the transradial or transfemoral approach, using 5F or 6F diagnostic catheters (Judkins, Amplatz, or universal-tip designs). Cine-fluoroscopic image acquisition in standardized orthogonal and angulated projections (RAO/LAO cranial/caudal views) generates the two-dimensional luminogram that defines lesion severity by percent diameter stenosis (DS%). This approach remains the procedural standard for elective and semi-urgent diagnostic workups globally.

TRANSRADIAL vs. TRANSFEMORAL ACCESS:

The transradial approach (TRA) is now the preferred default at all GAF Healthcare partner centers, supported by Level IA evidence from landmark trials (RIVAL, MATRIX). TRA reduces major access-site bleeding by 60–70%, eliminates the need for bed rest post-procedure (patients ambulate within 1–2 hours), shortens hospital stay to a single-day or overnight admission, and significantly reduces vascular complications compared to transfemoral access. The transfemoral approach remains available for cases with documented radial artery occlusion, severe forearm anatomy anomalies, or high-complexity ad-hoc PCI requiring large-bore access (7F–8F).

ADJUNCTIVE PHYSIOLOGICAL AND IMAGING MODALITIES:

• Fractional Flow Reserve (FFR): A pressure wire-derived ratio (coronary pressure distal to lesion / aortic pressure) measured during pharmacological hyperemia (adenosine infusion). FFR ≤ 0.80 indicates hemodynamically significant ischemia warranting revascularization. FFR-guided PCI has demonstrated superior outcomes over angiography-guided PCI in FAME and FAME-2 trials, reducing unnecessary stenting of non-flow-limiting lesions.

• Instantaneous Wave-Free Ratio (iFR): A resting-state adenosine-free pressure ratio (threshold ≤ 0.89), clinically non-inferior to FFR (DEFINE-FLAIR, iFR-SWEDEHEART trials), with faster procedural workflow and avoidance of adenosine side effects.

• Intravascular Ultrasound (IVUS): A 20–40 MHz rotational catheter providing cross-sectional, tomographic images of plaque burden, vessel remodeling, calcification depth, and minimum lumen area (MLA). IVUS-guided PCI is associated with lower rates of target vessel failure and stent thrombosis versus angiography-alone guidance (ULTIMATE, IVUS-XPL trials).

• Optical Coherence Tomography (OCT): Near-infrared light-based intracoronary imaging with 10–15 µm axial resolution, enabling differentiation of plaque phenotype (fibrous, calcified, lipid-rich, TCFA), assessment of fibrous cap thickness, and superior stent deployment optimization including edge dissection and incomplete stent apposition detection.

• Coronary CT Angiography (CCTA) — Pre-Procedural Planning: CCTA with fractional flow reserve derived from CT (FFRCT, HeartFlow®) may serve as a gatekeeper to invasive CAG, identifying patients who truly require catheterization (NXT, PLATFORM trials), reducing unnecessary procedures.

COMBINED DIAGNOSTIC + THERAPEUTIC (AD-HOC PCI):

When a hemodynamically significant lesion is confirmed at CAG, the interventional cardiologist — with patient consent obtained pre-procedure — may proceed directly to PCI using balloon angioplasty and drug-eluting stent (DES) implantation within the same session. Contemporary DES platforms (Resolute Onyx™, XIENCE™, Ultimaster Tansei™, Synergy™) feature biocompatible or biodegradable polymers eluting antiproliferative agents (zotarolimus, everolimus, biolimus) to minimize in-stent restenosis (ISR) rates to < 5–8% at 12 months.

SPECIALIZED HIGH-COMPLEXITY TECHNIQUES (AVAILABLE AT GAF HEALTHCARE PARTNER CENTERS):

• Rotational Atherectomy (Rotablator™): Burr-based plaque modification for heavily calcified, non-crossable lesions to enable adequate stent expansion.

• Orbital Atherectomy (Diamondback 360®): Alternative calcium modification tool for severely calcified coronary lesions.

• Intravascular Lithotripsy (Shockwave IVL, Shockwave Medical): Pulsatile ultrasonic energy delivered via a balloon catheter to fracture both intimal and medial calcium, facilitating stent delivery and expansion in calcified lesions.

• Laser Coronary Angioplasty (ELCA): Excimer laser for thrombus-laden lesions, balloon-uncrossable lesions, and in-stent restenosis.

• Chronic Total Occlusion (CTO) PCI: Advanced retrograde and antegrade wire escalation strategies (CART, Reverse CART) for complete coronary occlusions, performed by dedicated CTO operators with specialized training.

• Left Main and Bifurcation PCI: Techniques including provisional single-stenting, T-stenting, TAP, Culotte, and double-kissing (DK) Crush, guided by IVUS/OCT for precise ostial coverage.

PRE-PROCEDURE PHASE (Days -7 to 0):

Day -7 to -3 (Remote/Arrival): GAF Healthcare coordinates electronic transmission of all prior medical records, imaging (ECHO, stress test, CCTA), and laboratory results to the designated interventional cardiologist at the partner hospital. A tele-consultation is arranged for the patient to meet their cardiologist virtually, review findings, confirm the indication for CAG, discuss procedural risks and benefits, and obtain preliminary informed consent. Medication review is conducted: patients on anticoagulants (warfarin, NOACs) receive bridging or cessation instructions; metformin is typically withheld 48 hours before and after contrast exposure in patients with eGFR < 60 mL/min/1.73 m²; dual antiplatelet therapy (DAPT) instructions are issued based on clinical scenario.

Day -1 to 0 (Hospital Admission / Pre-Op Assessment): Patient is admitted to the hospital (or attends a pre-admission clinic for day-procedure cases). Baseline investigations are repeated or verified: ECG, CBC, renal function, coagulation, blood glucose, blood group. An allergy history is formally documented; patients with prior contrast reactions receive premedication (methylprednisolone 32 mg orally at 12 and 2 hours pre-procedure + diphenhydramine 50 mg IV/IM 1 hour pre-procedure). Renal protection protocol (IV 0.9% NaCl hydration at 1 mL/kg/hr for 3–12 hours pre-procedure) is initiated for patients with eGFR 30–60 mL/min/1.73 m². The radial artery is assessed with a modified Allen's test and Barbeau test to confirm ulnar collateral patency before committing to transradial access. The patient is kept NPO for 4–6 hours before the procedure.

PROCEDURE DAY:

Pre-Procedure (1–2 hours before): IV access is established. Baseline vital signs, SpO₂, and peripheral pulses are documented. Informed consent is reconfirmed and signed. Pre-procedural medications are administered: antiplatelet loading (aspirin 300 mg + clopidogrel 600 mg or ticagrelor 180 mg loading dose, if ad-hoc PCI is anticipated), heparin or bivalirudin anticoagulation protocol is selected. The patient is transferred to the cardiac catheterization laboratory (Cath Lab).

Intra-Procedure (30–90 minutes typical duration): 1. Patient is positioned on the fluoroscopy table; ECG monitoring, pulse oximetry, and blood pressure monitoring are attached. 2. The access site (typically right wrist for transradial) is sterilely prepped and draped. Local anesthetic (2% lidocaine) is infiltrated subcutaneously. 3. A 5F or 6F arterial sheath is placed using the Seldinger technique under fluoroscopic or ultrasound guidance. 4. A cocktail of vasodilators (verapamil 2.5–5 mg + nitroglycerin 100–200 µg) is administered intra-arterially to prevent radial artery spasm. 5. Diagnostic catheters (Judkins Left 3.5 or 4.0, Judkins Right 4.0, or universal catheters) are advanced to the coronary ostia under fluoroscopic guidance. 6. Iodinated contrast (iso-osmolar or low-osmolar, e.g., iodixanol or iopamidol) is injected while cine-fluoroscopic acquisitions are performed in multiple angulated projections. 7. Left ventriculography (LV-gram) may be performed to assess global and regional LV systolic function, identify wall motion abnormalities, and quantify the ejection fraction. 8. If FFR/iFR assessment is required, a pressure wire is advanced, and measurements are taken with or without adenosine infusion. 9. If IVUS or OCT is performed, the imaging catheter is advanced across the lesion and automated pullback images are acquired. 10. All images are reviewed in real time by the interventional cardiologist. The SYNTAX Score is calculated for multivessel disease. A Heart Team discussion may be initiated if CABG vs. PCI decision is non-straightforward. 11. If ad-hoc PCI is performed: balloon pre-dilation, stent selection and deployment, post-dilation with high-pressure non-compliant balloon, and final angiographic and physiological result assessment are completed. 12. The arterial sheath is removed (transradial: patent hemostasis band applied immediately, e.g., TR Band™; transfemoral: manual compression, closure device such as Angioseal™ or Perclose™, or compression band).

POST-PROCEDURE RECOVERY PHASE:

Hours 0–4 (Recovery Bay): Patient is monitored in the cardiac recovery area. Vital signs, ECG, and access site are checked every 15–30 minutes. Radial hemostasis band is progressively deflated per patent hemostasis protocol over 2 hours. The patient is encouraged to drink fluids to facilitate contrast excretion. Pain assessment is performed; analgesics are provided if needed.

Hours 4–6: Patient ambulates (transradial cases); oral intake is resumed. Repeat renal function testing is ordered for high-risk CKD patients at 24–48 hours. Preliminary results discussion with the cardiologist occurs: the patient is counseled on findings, SYNTAX Score (if applicable), and recommended next steps (medical management, PCI, or CABG referral).

Day 1 (Discharge): Most patients undergoing diagnostic-only CAG via transradial access are discharged the same day or after one overnight observation. A formal discharge summary, procedural report, and CD/images of angiography are provided to the patient. Medications are prescribed: DAPT (aspirin + clopidogrel/ticagrelor) if stenting was performed; antianginals, statins (high-intensity: atorvastatin 40–80 mg or rosuvastatin 20–40 mg), ACE inhibitor/ARB, and beta-blockers as indicated. Wound care instructions for the radial site are given.

Day 2–5 (Post-Discharge Recovery): Patient recuperates at accommodation arranged by GAF Healthcare near the hospital. Radial access site is monitored for hematoma, swelling, or signs of radial artery occlusion. Light activities are permitted. Wrist-gripping activities and heavy lifting (> 2 kg) are restricted for 5–7 days. A virtual follow-up consultation with the cardiologist is arranged.

Day 5–7 (Fit-to-Fly Assessment): The cardiologist formally assesses fitness for air travel. Criteria include: stable access site without active hematoma or vascular complication, hemodynamic stability, no arrhythmia requiring monitoring, no post-contrast renal dysfunction requiring ongoing IV management, and patient understanding of medication compliance. Medical summary and fitness-to-fly letter are issued by GAF Healthcare partner hospital for airline requirements.