PhD Degree Awarded to Researcher Nawar Al-Wather in Cardiology

Researcher Nawar Ali Mohammed Al-Wather ‎was awarded a PhD degree in Cardiology ‎for her dissertation titled: The Predictive Value of D-Dimer Levels for Detecting Left Atrial Thrombus in Patients with Rheumatic Heart, which was submitted to the Department of Cardiology, Faculty of Medicine and Health Sciences – Sana’a University. The dissertation defense was held on Thursday, August 27, 2026.

The PhD Viva-Voce Committee, which was formed based on a resolution issued by the Graduate Studies and Scientific Research Council, consisted of the following:

• Mohammed Mohammed Al-Kebsi – Sana’a University – Principal Supervisor and Committee Member.

• Ahmed Lotf Al-Mutarrib – Sana’a University – Internal Examiner and Committee Chair.

• Aziz Saleh Al-Zindani – Sana’a University – External Examiner and Committee Member.

The dissertation aimed to evaluate the diagnostic accuracy of the D-dimer blood test as an independent biomarker for ruling out left atrial thrombus in patients with severe rheumatic mitral stenosis, and to provide a rapid and safe medical alternative that could reduce the need for transesophageal echocardiography (TEE). This could help expedite clinical decision-making, particularly given the limited availability and high cost of TEE.

The study yielded several important findings, most notably identifying 360.6 ng/mL as the optimal cutoff value for ruling out thrombus, achieving 100% accuracy in the study sample. By contrast, the conventional clinical cutoff of 500 ng/mL was insufficient to rule out some cases, as it failed to detect 25% of active cases within the studied group.

The statistical models also demonstrated that D-dimer testing is a strong and independent biomarker, while other factors, including atrial fibrillation and mitral valve area, did not provide additional diagnostic value beyond that obtained from D-dimer testing alone.

Among patients whose results were not affected by anticoagulant medications, the study revealed a strong association between severe left atrial enlargement and elevated D-dimer levels. The mean left atrial diameter was 59.0 mm, reflecting the relationship between structural cardiac changes and the biological activity associated with thrombus formation.

The researcher recommended incorporating D-dimer testing into the routine assessment of patients with rheumatic heart disease before percutaneous transvenous mitral commissurotomy (PTMC) or electrical cardioversion. This would help identify low-risk patients and reduce the need to wait for TEE.