Sclerodegenerative aortic valve disease represents a progressive structural continuum driven by lipid accumulation, chronic mechanical shear stress, and fibro-calcific remodeling of native valvular leaflet matrices. As micro-calcific deposits coalesce into macroscopic nodular calcification, the result is a progressively obstructive orifice, imposing severe systolic afterload upon the left ventricle. When uncorrected, this chronic pressure overload inevitably precipitates concentric left ventricular hypertrophy, diastolic dysfunction, secondary atrial and pulmonary vascular remodeling, and ultimately, cardiac decompensation.

TAVR has fundamentally transformed the landscape of structural heart intervention. Having originated as a salvage strategy for inoperable candidates, it has matured into a preferred modality across low-, intermediate-, and high-surgical-risk populations. Procedural outcomes, however, remain critically dependent on the quality and granularity of pre-procedural anatomical evaluation. The spectrum of potential complications — paravalvular leak, coronary ostial obstruction, conduction disturbance, and annular rupture — can be substantially mitigated through meticulous pre-interventional imaging.

Among anatomical hazards, a left coronary artery ostial height below the conventional 10 mm safety boundary constitutes one of the most feared risk factors for catastrophic procedural failure. During transcatheter heart valve (THV) expansion, native calcified leaflets are displaced superiorly and laterally, potentially occluding coronary inflow when the coronary ostium is situated too proximally. This risk is further amplified when the native leaflet length exceeds the coronary ostial height, creating a geometric scenario in which the displaced leaflet may directly shield or block coronary perfusion.

This manuscript presents a comprehensive analysis of multi-phase MDCT corelab evaluation utilizing 3mensio structural heart software, peripheral vascular mapping, virtual valve deployment simulation, and post-procedural echocardiographic outcomes in a patient with severe fibro-calcific aortic stenosis presenting with a critically low LCA ostial height. The case underscores the necessity of granular computational pre-procedural planning in anatomically complex TAVR candidates.

2. Case Presentation and Pre-Procedural Assessment

2.1 Patient Demographics and Clinical Profile

The patient was a 72-year-old female who presented with NYHA Class III cardiovascular symptoms, characterized by advanced exertional dyspnea, progressive functional limitation, and restricted daily activity. No prior cardiac interventional history was documented. Initial triage confirmed a diagnosis of symptomatic severe aortic stenosis with concomitant moderate aortic regurgitation.

2.2 Electrocardiographic Findings

Baseline 12-lead electrocardiography demonstrated sinus tachycardia with concurrent sinus arrhythmia at a heart rate of 102 bpm. Detailed electro-conduction parameters included a PR interval of 174 ms, QRS duration of 69 ms, and a QT/QTc interval of 347/453 ms. Repolarization abnormalities were evident, with marked ST-segment depression in lead V4 and concomitant ST-segment elevation in lead V5, consistent with sub-endocardial ischemic burden secondary to pressure overload. High-voltage criteria confirmed advanced left ventricular hypertrophy paired with left atrial enlargement.

Figure 1. Baseline 12-Lead ECG demonstrating sinus tachycardia (102 bpm), ST-segment depression in V4, ST elevation in V5, left atrial enlargement, and left ventricular hypertrophy — consistent with severe pressure overload.

2.3 Transthoracic Echocardiographic Assessment

Baseline 2D transthoracic echocardiography with multi-directional color Doppler interrogation confirmed advanced sclerodegenerative aortic valve disease. The aortic valve demonstrated severely thickened, highly calcific leaflets establishing critical stenosis co-existent with moderate aortic regurgitation, with an AR pressure half-time (PHT) of 325 ms. Quantitative hemodynamic parameters are summarized in Table 1.

Table 1. Baseline Pre-Procedural 2D Echocardiographic Parameters. AS = Aortic Stenosis; AR = Aortic Regurgitation; EF = Ejection Fraction; IVSd = Interventricular Septal Thickness in Diastole; LVIDd = LV Internal Diameter in Diastole; PAH = Pulmonary Arterial Hypertension; RVSP = Right Ventricular Systolic Pressure.

Left ventricular remodeling parameters confirmed mild concentric hypertrophy (IVSd 1.4 cm, PWd 1.5 cm) with mildly dilated cavity (LVIDd 5.4 cm) and preserved systolic function (LVEF 55%). Left atrial dilation was noted (LA AP diameter 4.5 cm), reflecting chronic pressure overload. Concomitant Grade II mitral regurgitation and Grade I tricuspid regurgitation were present. Right ventricular systolic pressure was elevated at 45 mmHg, confirming secondary moderate pulmonary arterial hypertension. No intracardiac thrombus or pericardial effusion was identified.

3. Multidetector Computed Tomography Corelab Evaluation

Electrocardiogram-gated multi-detector computed tomography (MDCT) was performed on 10 October 2025 and submitted to the Meril TAVI CoreLab for analysis utilizing 3mensio Structural Heart software version 10.4 SP2. Analysis was conducted across multiple cardiac phases to characterize dynamic changes in aortic root geometry and maximize anatomical sizing precision.

3.1 Corelab Summary Report

The corelab report identified a tricuspid aortic valve architecture with mild fibro-calcific involvement. The aortic annulus demonstrated broader dimensions during the late diastolic phase (86%) compared to the early systolic phase (39%), a finding of practical significance for device sizing. The sub-annular LVOT spatial cross-section was noted to closely approximate the true annular basal plane, and a critically low LCA ostial height of 9.3 mm was flagged as a primary procedural risk factor.

3.2 Multi-Phase Annular Planimetry

Corelab reconstruction confirmed significant phasic variation in aortic annular geometry between systolic and diastolic phases (Table 2). The area-derived diameter increased from 19.2 mm in systole (area 289.4 mm²) to 19.9 mm in diastole (area 311.4 mm²), representing a 7.6% increase in luminal cross-sectional area. The perimeter-derived diameter progressed from 20.0 mm to 20.5 mm, while mean annular diameter rose from 18.6 mm to 20.8 mm. The eccentricity coefficient improved marginally from 0.31 in systole to 0.28 in diastole, indicating a modestly more circular annular profile during diastolic filling. These variations carry direct implications for device sizing: reliance on systolic phase alone would systematically underestimate the true maximal annular dimension, potentially leading to device undersizing and paravalvular regurgitation.

Figure 2. 3mensio Structural Heart Corelab Summary Report (Meril TAVI CoreLab) — Key metrics: Perimeter-derived Ø 20.5 mm, Area-derived Ø 19.9 mm, LCA Height 9.3 mm (low), RCA Height 11.4 mm. Analysis phase: 86% diastolic.

Table 2. Multi-Phase MDCT Aortic Annular and LVOT Dimensions (3mensio Corelab). LVOT = Left Ventricular Outflow Tract. All measurements obtained via 3mensio Structural Heart 10.4 SP2.

The sinotubular junction (STJ) demonstrated a stable mean diameter of 26.9 mm (range 25.7–28.1 mm), and the ascending aorta measured 28.1 mm (range 27.6–28.7 mm). The sinus of Valsalva showed an asymmetric configuration with left sinus 29.2 mm, non-coronary sinus 27.6 mm, and right sinus 26.6 mm. Mean sinus height measured 10.6 mm.

3.3 Coronary Ostial Height Assessment and VTC Simulation

A critical anatomical risk identified during corelab evaluation was an LCA ostial height of 9.3 mm, which is below the internationally accepted 10 mm safety threshold for TAVR. The right coronary artery (RCA) height was comparatively safer at 11.4 mm. This low LCA clearance was further compounded by the native left leaflet length of 12.2 mm — exceeding the coronary ostial height by 2.9 mm — raising the possibility that during bioprosthetic expansion, the displaced native leaflet could shield or occlude the LCA ostium.

To quantify this risk, a 3D virtual valve deployment simulation was performed using a 21.5 mm valve framework. The resulting valve-to-coronary (VTC) clearance distance was measured at 6.1 mm, with a mean neo-sinus tissue density of 307 Hounsfield Units (HU). A VTC distance exceeding 4–5 mm is generally considered indicative of adequate coronary perfusion reserve following valve deployment. The computed 6.1 mm clearance, therefore, supported a primary transfemoral approach without prophylactic coronary protection measures.

Figure 3. Multi-Phase Annular Planimetry (3mensio) — Comparative cross-sectional annular and LVOT planimetric reconstructions at systolic (39%) and diastolic (86%) phases. Diastolic phase demonstrates larger annular and LVOT dimensions compared to systole.

Figure 4. Coronary Ostial Heights and VTC Simulation (3mensio) — LCA height 9.3 mm (critically low, <10 mm threshold); RCA height 11.4 mm; Virtual valve-to-coronary distance on 21.5 mm valve simulation = 6.1 mm; Native left leaflet length 12.2 mm.

3.4 Fluoroscopic Angle and Commissural Alignment Planning

Optimal fluoroscopic projection angles for aortography and valve deployment were computed from MDCT data. The standard aortography working angle was determined at RAO 41° / Caudal 19°. The right-left cusp overlap view was projected at RAO 50° / Caudal 27°, and the prosthesis commissural alignment (cusp-symmetry) view was oriented at RAO 95° / Cranial 52°. The optimal commissural alignment strategy targeted the native right coronary cusp midpoint at a 02:58 o’clock clock-face configuration, facilitating accurate rotational deployment alignment.

Figure 5. Sinotubular Junction, Ascending Aorta, Fluoroscopic Deployment Angle, and Right-Left Cusp Overlap View — Pre-computed optimal projection angles for aortography and commissural alignment (RAO 41°/Caudal 19° and RAO 50°/Caudal 27°)

Figure 6. Commissural Clock Angle Alignment — Mid Right Coronary Cusp (RCC) and RCA clock-face mapping. Optimal cusp-symmetry view (RAO 95°/Cranial 52°) and target commissural alignment at 02:58 o’clock configuration.

3.5 Calcium Volumetric Indexing and Aortic Root Morphology

Targeted calcium scoring confirmed a globally low calcification burden localized exclusively to the native valvular apparatus. Total calcium volume was 85 mm³, predominantly concentrated in the left coronary cusp (LC: 76 mm³), with minor involvement of the non-coronary cusp (NC: 9 mm³) and complete absence from the right coronary cusp (RC: 0 mm³). No descending thoracic or abdominal aortic calcification was identified, though mild atheromatous calcific change was noted at the aortic arch. This distribution indicates preferential lipid and shear stress loading at the LC cusp interface, consistent with reported biomechanical patterns in fibro-calcific degeneration.

Figure 7. Calcium Distribution and Aortography Angle — Calcium predominantly localized to the left coronary cusp (76 of 85 mm³ total). Mild arch calcification. Aortography working angle RAO 41°/Caudal 19°. Right, non-coronary cusps show minimal-to-absent calcification.

Figure 8. Aortic Root MIP and Volume Rendering (VR) Reconstructions — Double oblique MPR and 3D VR views demonstrating tricuspid valve anatomy, sinus of Valsalva asymmetry, and spatial relationship of annular plane to surrounding structures.

4. Peripheral Vascular Access Evaluation

A complete bilateral iliofemoral access study was conducted to assess the feasibility of large-bore transfemoral delivery sheath insertion. Quantitative luminal measurements were obtained for both right and left access vectors across the common iliac, external iliac, and common femoral artery segments (Table 3).

Table 3. Bilateral Iliofemoral Access Measurements (3mensio Peripheral Vascular Analysis). CIA = Common Iliac Artery; EIA = External Iliac Artery; FA = Femoral Artery. Values presented as mean (range). No calcification identified in any segment.

All vascular segments demonstrated widely patent lumina without calcific deposits or significant tortuosity. Minimum luminal diameters across both iliofemoral vectors remained comfortably above the 6.3 mm threshold required for 19-French delivery sheath insertion. Given the absence of calcification and adequate luminal calibers, uncomplicated transfemoral access was anticipated, and the right femoral artery was selected as the primary arteriotomy site.

Figure 9. Bilateral Femoral Access Data (3mensio) — Right: CIA 8.2 mm, EIA 5.6 mm, FA 7.5 mm. Left: CIA 7.0 mm, EIA 5.8 mm, FA 7.0 mm. No calcification in any segment bilaterally.

Figure 10. Femoral Vascular Overview — 3D angiographic reconstruction demonstrating widely patent bilateral iliofemoral systems. Sufficient minimum luminal diameters for transfemoral large-bore sheath delivery confirmed.

Figure 11. Iliofemoral Snake View (3mensio) — Straightened vessel lumen analysis of right and left iliac arteries confirming consistent luminal caliber without stenosis, calcification, or tortuosity.

5. Procedural Execution and Post-Operative Outcomes

Following multidisciplinary heart team evaluation and informed consent, the patient underwent successful transfemoral TAVR under general anesthesia at Synergy Multispeciality Hospital, Miraj, under the care of Dr. Tushar Dhopade. A 21.5 mm bioprosthesis was deployed under fluoroscopic guidance utilizing pre-planned projection angles derived from corelab data. Post-procedural transthoracic echocardiography with color Doppler interrogation was performed to evaluate prosthesis function, hemodynamic restoration, and complications. Key outcomes are summarized in Table 4.

Table 4. Comparative Pre- and Post-TAVR Hemodynamic and Structural Outcomes. PVL = Paravalvular Leak; LV = Left Ventricle; LVIDd = LV Internal Diameter in Diastole.

The transcatheter bioprosthesis was confirmed as stable and well-seated within the native annulus without structural migration, malposition, or embolization. Hemodynamic interrogation demonstrated a 74% reduction in peak transvalvular pressure gradient (from 80 mmHg to 21 mmHg) and a mean gradient of 11 mmHg, reflecting excellent prosthetic hemodynamic function. Peak jet velocity declined from 4.4 m/s to 2.7 m/s. Complete resolution of native moderate aortic regurgitation was confirmed, with no trace central or paravalvular leak detected on color Doppler assessment.

Left ventricular systolic function remained preserved at an ejection fraction of 55%. Early favorable structural remodeling was suggested by a marginal reduction in LVIDd from 5.4 cm to 5.3 cm. Secondary valvular pathology remained stable, with mitral regurgitation at Grade II and tricuspid regurgitation at Grade I. Right ventricular systolic pressure remained 45 mmHg, consistent with pre-existing moderate pulmonary arterial hypertension expected to improve on serial follow-up. No pericardial effusion, conduction disturbance requiring permanent pacing, vascular access complication, or stroke was recorded.

6.1 Fibro-Calcific Aortic Stenosis and the Case for Corelab Analysis The natural history of fibro-calcific aortic stenosis follows a well-characterized trajectory from subclinical leaflet sclerosis to severe, hemodynamically obstructive stenosis. The coexistence of moderate aortic regurgitation in this case reflects advanced multi-directional valvular failure, with calcific nodules disrupting both leaflet coaptation and excursion. This combined valvular pathology substantially elevates post-stenotic LV volume work, accelerating adverse remodeling. The role of dedicated TAVR corelab analysis has expanded considerably as procedural complexity increases. In standard cases, corelab evaluation confirms sizing and access feasibility. In anatomically hostile cases such as this — characterized by low coronary ostial clearance, asymmetric sinus geometry, and significant phasic annular variation — corelab evaluation transitions from a confirmatory tool to an essential risk-stratification and simulation platform. The 3mensio Structural Heart platform utilized at the Meril TAVI CoreLab provides multi-plane reconstructions, phase-specific planimetry, calcium volumetric mapping, VTC distance calculation, and fluoroscopic angle prediction in an integrated workflow. 6.2 Coronary Occlusion Risk and the VTC Distance Framework Coronary artery obstruction following TAVR, while uncommon (reported incidence approximately 0.3–0.9% in large registries), carries a mortality rate exceeding 40% when it occurs. Risk is maximized when multiple anatomical factors converge: low coronary ostial height (<10 mm), a bulky or elongated native leaflet that exceeds the coronary ostial height, a shallow sinus of Valsalva, and a small valve-to-coronary distance. This patient met two of these criteria simultaneously — LCA height of 9.3 mm and a left leaflet length of 12.2 mm that exceeded the ostial height by 2.9 mm. The VTC distance, defined as the shortest computed distance between the deployed transcatheter valve frame and the coronary ostium, has emerged as a quantifiable surrogate for occlusion risk. Emerging consensus suggests a VTC distance below 4 mm as high risk and above 5–6 mm as relatively safe. The 6.1 mm VTC clearance computed in this case on a 21.5 mm virtual valve framework placed the patient above accepted risk thresholds, supporting standard deployment without prophylactic chimney stenting or guidewire coronary protection. Post-procedural verification of intact coronary perfusion confirmed the adequacy of this risk stratification. 6.3 Dynamic Annular Geometry and Phase-Specific Sizing Strategy Aortic annular geometry is not static; it undergoes measurable phasic variation throughout the cardiac cycle. The annulus is maximal during mid-to-late diastole and minimal during systole, with the degree of variation influenced by annular composition, the extent of calcification, and overall cardiac performance. In this case, the area-derived annular diameter increased by 3.6% between systolic and diastolic phases, while the mean annular diameter increased by 11.8%. Although individual measurements may vary depending on reconstruction software, these observed differences are clinically meaningful when selecting a device size that avoids both under-sizing (predisposing to paravalvular leak) and over-sizing (predisposing to annular injury or conduction abnormality). International consensus guidelines now recommend the use of late diastolic (70–80% R-R phase) reconstructions as the primary sizing reference for TAVR. This patient’s late diastolic reconstruction at 86% phase provided the most accurate representation of maximal annular caliber, and valve selection based on this measurement yielded excellent hemodynamic outcomes without paravalvular regurgitation. 6.4 Calcium Distribution and Its Procedural Implications Calcium distribution across the aortic valve has a multifaceted impact on TAVR outcomes. Heavy circumferential calcification at the aortic annular level predisposes to annular injury and conduction disturbance. Asymmetric calcification, particularly when concentrated within a single cusp, may result in asymmetric device expansion, localized paravalvular gaps, and suboptimal hemodynamic function. In this patient, calcium was predominantly concentrated in the left coronary cusp (76 of 85 mm³ total), with a clean right coronary cusp and minimal non-coronary cusp involvement. This asymmetric, mild calcification profile was favorable for device expansion and likely contributed to the complete absence of paravalvular leak observed post-procedurally. 6.5 Transfemoral Access and Vascular Safety Transfemoral TAVR is associated with superior clinical outcomes compared to alternative access routes, including lower major vascular complication rates, shorter hospital stay, and reduced procedural complexity. Patient eligibility for transfemoral access is determined primarily by the minimum luminal diameter of the iliofemoral system relative to the delivery sheath profile and the extent of calcific plaque and tortuosity. In this case, bilateral iliofemoral vessels demonstrated entirely adequate calibers (minimum EIA diameter 5.4 mm bilaterally), no calcification, and no significant tortuosity, confirming uncomplicated large-bore access feasibility.

This case demonstrates that technically safe and hemodynamically successful TAVR can be executed in patients with fibro-calcific aortic stenosis presenting with anatomically hostile coronary configurations, provided that pre-procedural planning is anchored by comprehensive multi-phase MDCT corelab evaluation. Key learnings from this case include:

• Multi-phase MDCT corelab analysis is indispensable for accurate annular sizing in patients with dynamic annular geometry. Diastolic phase reconstructions should serve as the primary sizing reference to prevent device undersizing and paravalvular regurgitation.
• Virtual 3D VTC simulation provides a quantifiable, reproducible metric for coronary occlusion risk stratification in patients with low coronary ostial height. A VTC distance exceeding 5–6 mm supports standard deployment without prophylactic coronary protection.
• Asymmetric, mild cusp-confined calcification is associated with favorable device expansion and low paravalvular regurgitation risk.
• Bilateral iliofemoral vascular mapping enables objective selection of the optimal access route and anticipates potential access-related complications prior to intervention.
• Integrated use of dedicated structural heart corelab platforms such as 3mensio Structural Heart facilitates consistent, reproducible pre-procedural planning across all relevant anatomical domains.

The implementation of rigorous multi-modal corelab analytics represents an evolving standard of care that enables operators to safely extend TAVR eligibility to anatomically complex patient profiles previously considered prohibitively high risk.