Danial Ahmad

Dr. Danial Ahmad


Research Focus & Metrics

Academic Career Length

2Years (2025-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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15 December 2025 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
STSriharsha Talapaneni
Sriharsha Talapaneni
DADanial Ahmad
Danial Ahmad
MKMeghna Khandelwal
Meghna Khandelwal
MMMonica Mesiha
Monica Mesiha
PJPooya Jalali
Pooya Jalali
PVPrashanth Vallabhajosyula
Prashanth Vallabhajosyula
Objective: Prosthesis–patient mismatch (PPM) occurs after aortic valve replacement (AVR) when the effective orifice area of the implanted prosthetic valve is small relative to the patient’s body surface area. Beyond simply elevating transvalvular gradient, PPM profoundly affects cardiac remodeling, coronary physiology, and ultimately patient survival. This comprehensive review synthesizes current evidence regarding PPM pathophysiology, clinical consequences, and therapeutic strategies. Methods: We conducted a narrative review of PPM in surgical (SAVR) and transcatheter (TAVR) aortic valve replacement. PubMed and Embase were systematically searched using terms related to AVR and PPM and reference lists of key studies and reviews were screened. Studies addressing PPM prevalence, hemodynamic impact, clinical outcomes, and mitigation strategies were included. Results: PPM, defined as an iEOA ≤ 0.85 cm2/m2 (moderate) or ≤0.65 cm2/m2 (severe), demonstrates variable prevalence across studies, typically ranging from 5 to 30% after SAVR and 2–35% after TAVR. It is associated with increased transvalvular gradients, reduced left ventricular mass regression, persistent coronary flow abnormalities, higher rates of heart failure, and both early and late mortality. Supra-annular self-expanding transcatheter aortic valve replacement (TAVR) devices and newer generation stentless or bovine pericardial surgical valves exhibit lower PPM rates than older stented or porcine valves. Valve-in-valve (ViV) TAVR and bioprosthetic valve fracture (BVF) can improve outcomes in failed surgical valves but are less effective in small annuli. TAVR-in-TAVR procedures are limited by anatomic and technical constraints, especially in maintaining coronary access and minimizing residual gradients. Conclusions: PPM remains a common and clinically consequential complication of AVR that compromises long-term outcomes. It is largely preventable through accurate preoperative imaging, valve sizing, and consideration of annular enlargement. Optimal outcomes require matching valve characteristics to individual patient anatomy and physiology. In an era of expanding TAVR use, preventing PPM during the index procedure is critical to optimizing survival and preserving future reintervention options.

28 April 2026 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
ARAsama Rana
Asama Rana
IHIrbaz Hameed
Irbaz Hameed
SDSedem Dankwa
Sedem Dankwa
DADanial Ahmad
Danial Ahmad
CBCameron Best
Cameron Best
PVPrashanth Vallabhajosyula
Prashanth Vallabhajosyula
Objectives: Several measurement techniques have been proposed to address the non-circular geometry of the aortic root. The Laplace diameter metric incorporates the cloverleaf anatomy of the aortic root and is derived via measurement of sinus-to-commissure lengths with subsequent doubling of the largest radius from the center. This study compares the conventional sinus-to-sinus with the novel Laplace method for sizing the aortic root and quantifying its implication on surgical decision-making. Methods: Patients undergoing surveillance at a high-volume aortic center were categorized by aortic root morphology as nondilated, non-syndromic dilated, bicuspid aortic valve and Marfan syndrome. Aortic root diameters by sinus-to-sinus and Laplace diameter methods were measured on computed tomography, compared using paired t-tests, and correlated using Spearman rank coefficients. Results: Of the 1297 patients assessed, 530 were included in the final analysis (nondilated n = 113, non-syndromic dilated n = 347, bicuspid aortic valve n = 50, Marfan syndrome n = 17). Aortic root diameters were significantly larger by Laplace than sinus-to-sinus diameter across all groups (sinus-to-sinus: 1.9 ± 5.5 mm; Laplace: 44.9 ± 7.0 mm; 95% confidence interval 2.72–3.34; p < 0.0001). Although Laplace and sinus-to-sinus diameter were correlated (Spearman r = 0.6789, 95% CI 0.6–0.7; p < 0.0001), the relationship was non-linear (R2 = 0.492). Laplace diameter increased the proportion of patients meeting surgical thresholds (2022 AHA/ACC guidelines) versus sinus-to-sinus: nondilated 0% vs. 1.77%, non-syndromic dilated 4.9% vs. 25.1%, bicuspid aortic valve 10.0% vs. 26.0%, and Marfan syndrome 23.5% vs. 52.9%. Conclusions: On average, Laplace diameter exceeded sinus-to-sinus diameter by 3 mm and would extend surgical eligibility to an additional 21% of patients under current guidelines.

Verified
Journal Article
Open access
PDF file
Nafiye Busra CelikNafiye Busra Celik
Nafiye Busra Celik
DADanial Ahmad
Danial Ahmad
AFAsad Saulat Fatimi
Asad Saulat Fatimi
STSriharsha Talapaneni
Sriharsha Talapaneni
MQMahid Qureshi
Mahid Qureshi
PVPrashanth Vallabhajosyula
Prashanth Vallabhajosyula
The aortic arch remains one of the most complex segments of the thoracic aorta to treat, demanding strategies that safeguard cerebral and spinal perfusion while achieving durable proximal and distal repair. Contemporary management strategies include open hemi/total arch replacement, hybrid approaches such as frozen elephant trunk (FET) or debranching with thoracic endovascular aortic repair (TEVAR), and fully endovascular repair using branched or fenestrated devices. Updated guidelines (American College of Cardiology/American Heart Association [ACC/AHA] 2022; European Society of Cardiology [ESC] 2024) emphasize multidisciplinary, patient-specific decision-making grounded in standardized imaging, genetics, and lifelong surveillance. Procedurally, selective antegrade cerebral perfusion with moderate-to-low hypothermia has replaced routine deep hypothermic circulatory arrest for most open arch operations. Zone-based planning using Ishimaru’s map, complemented by the Modified Arch Landing Areas Nomenclature (MALAN), improves feasibility assessment and risk stratification, while entry-focused schemas like TEM (Type, Entry, Malperfusion) further refine management. Emerging data indicate that open repair remains the durability benchmark in younger populations and those with connective tissue disease, and FET enables single-stage treatment capability with acceptable early outcomes but requires vigilant neurologic protection and reintervention surveillance. An integrated, zone-driven approach guided by center expertise optimizes patient selection for open, hybrid, or endovascular options to maximize safety and durability.