The lowest mitral valve area successfully treated by PTMC: a rare case

Abstract

We present a detailed case of a 39-year-old male patient with severe, symptomatic rheumatic mitral stenosis who was successfully treated with percutaneous transvenous mitral commissurotomy (PTMC) at Milad Hospital in Isfahan, Iran. The patient presented with chronic dyspnea on exertion (New York Heart Association class III) and fatigue, and pre-procedural two-dimensional and three-dimensional echocardiography confirmed a critically low mitral valve area (MVA) of 0.36 cm (3D planimetry with multiplanar reconstruction) and a challenging valve morphology, as assessed by a high Wilkins score of 10 and a 3D echocardiographic score of 8. The PTMC procedure, performed with an Inoue balloon, was uneventful and resulted in a marked improvement in valve function, with the MVA increasing to and the systolic pulmonary artery pressure decreasing from 45 mmHg to 30 mmHg. Mitral regurgitation remained trivial/mild (grade 1+) throughout. At one-month follow-up, the patient was in NYHA class II and the MVA remained stable. This case highlights that PTMC remains a highly effective and safe intervention for severe mitral stenosis, even in patients with high-risk valve morphology, when performed by experienced operators in a specialized tertiary care center and guided by a multidisciplinary Heart Team.

Introduction

Mitral stenosis (MS), a progressive valvular heart disease, is a major cause of morbidity and mortality worldwide, particularly in developing countries where rheumatic fever is still endemic [1]. The disease is characterized by the narrowing of the mitral valve orifice, which obstructs blood flow from the left atrium (LA) to the left ventricle (LV). This obstruction leads to a cascade of hemodynamic changes, including increased LA pressure, LA enlargement, and subsequent pulmonary hypertension, which can ultimately culminate in right heart failure. For symptomatic patients with suitable valve anatomy, percutaneous transvenous mitral commissurotomy (PTMC) has been the gold standard for non-surgical intervention since its introduction by Inoue in 1984 [2].

Patient selection is critical for the success of PTMC. The Wilkins score, an echocardiographic scoring system based on the degree of leaflet mobility, leaflet thickening, subvalvular thickening, and valvular calcification, is widely used to predict procedural success and the risk of complications [3]. A score of ≤ 8 is generally associated with optimal outcomes, while scores greater than 8 indicate more advanced disease, challenging anatomy, and a higher probability of procedural failure or post-procedural complications such as significant mitral regurgitation [4, 5]. However, additional anatomical details, particularly commissural morphology and calcification, can be obtained by three-dimensional (3D) echocardiography and integrated into scoring systems such as the Anwar score, which further refines risk stratification. Despite this, with advancements in operator skill and imaging guidance, successful outcomes are increasingly being reported in patients with high Wilkins scores, underscoring the importance of individualized patient assessment by a multidisciplinary Heart Team.

Case presentation

A 39-year-old male presented to our cardiology clinic at Milad Hospital with a chief complaint of progressively worsening dyspnea on exertion and chronic fatigue over the past six months. He was classified as New York Heart Association (NYHA) functional class III. His medical history was significant for a confirmed episode of rheumatic fever in childhood. Physical examination revealed a low-volume pulse, a loud first heart sound (S1), an audible opening snap, and a low-pitched diastolic rumbling murmur at the apex, consistent with severe mitral stenosis.

To confirm the diagnosis and assess the severity of the condition, a comprehensive advanced transthoracic echocardiogram was performed. The two-dimensional (2D) echocardiographic evaluation revealed severely thickened and calcified mitral valve leaflets with restricted mobility, consistent with rheumatic etiology. Three-dimensional (3D) data sets were acquired and analyzed using multiplanar reconstruction (MPR) to obtain an accurate planimetric mitral valve area (MVA) of on the en face view of the mitral orifice. The Wilkins score was calculated to be 10, with individual scores as follows: leaflet thickness (3), calcification (3), mobility (2), and subvalvular thickening (2). In addition, a dedicated 3D echocardiographic assessment of commissural morphology was performed. The 3D en face view demonstrated severe, asymmetric fusion of both commissures with a small, eccentric orifice and extensive leaflet calcification, corresponding to a 3D echocardiographic score (Anwar score) of 8, which further confirmed the high-risk anatomy. Doppler measurements showed a pressure half-time (PHT) of 280 ms (MVA by PHT ); however, PHT is known to overestimate MVA in the presence of severe left atrial enlargement, altered compliance, and concomitant mild aortic regurgitation, so 3D planimetry was considered the reference method. Mitral regurgitation was trivial (grade 0–1+) pre-procedure.

The full set of pre-procedural echocardiographic findings are detailed in the tables below, which also show significant left atrial enlargement and mild pulmonary hypertension, common sequelae of severe MS [6] (Tables 1, 2 and 3).

Table 1.

Echocardiographic parameters of left ventricle and atrium

Parameter	Pre-PTMC value	Reference range	Notes
LV size (LVEDDI)	3.1 cm/m	2.5–3.6 cm/m	Normal
LV volume (LVEDVI)	49 cc/m	35–65 cc/m	Normal
LV systolic function (EF)	55%	≥55%	Normal
LV diastolic function (septal e’)	5.1 cm/s	≥5 cm/s	Normal
LV diastolic function (lateral e’)	7.9 cm/s	≥7.5 cm/s	Normal
Left atrial diameter (LA AP D)	4.9 cm	2.7–4.0 cm	Severe Enlargement
Left atrial volume (LAVI)	70 cc/m	16–34 cc/m	Severe Enlargement

Table 2.

Echocardiographic parameters of right ventricle and associated valves

Parameter	Pre-PTMC value	Reference range	Notes
RV size (base)	4 cm	2.5–4.2 cm	Normal
RV systolic function (TAPSE)	21 mm	≥17 mm	Normal
RV systolic function (RVSm)	10 cm/s	≥9.5 cm/s	Normal
Right atrial volume (RAVI)	15 cc/m	15–25 cc/m	Normal
Tricuspid annulus diameter	3.2 cm	2.8–3.5 cm	Normal
Tricuspid regurgitation gradient (TRG)	40 mmHg	<30 mmHg	Mild TR
Estimated pulmonary artery pressure (sPAP)	45 mmHg	<30 mmHg	Mild Pulmonary Hypertension

Table 3.

Mitral valve assessment

Parameter	Pre-PTMC value	Post-PTMC value	Notes
Mitral valve area (MVA) by 3D planimetry (MPR)	0.36 cm	0.6 cm	Significant improvement
MVA by pressure half-time	0.79 cm(PHT 280 ms)	1.39 cm(PHT 158 ms)	PHT overestimates; complementary
Mitral valve morphology	Dome AMVL, Restricted PMVL, severe commissural fusion	Improved opening, partial commissural splitting	Consistent with rheumatic MS
Wilkins score (Total: 10)	Thickness (3), Calcification (3), Mobility (2), Subvalve (2)	–	High-risk anatomy
3D Echocardiographic score (Anwar)	8	–	Unfavorable commissural morphology
Mitral regurgitation frade	Trivial (0–1+)	Mild (1+)	No significant change
NYHA functional class	III	II	Marked symptomatic relief
Estimated sPAP (mmHg)	45	30	Significant hemodynamic improvement

The patient was evaluated by a multidisciplinary Heart Team. In view of his young age, absence of significant mitral regurgitation, and his strong, informed refusal of surgical intervention, a decision was made to attempt PTMC with a stepwise balloon inflation technique, keeping the surgical option as a bailout.

Procedure and outcome

The patient was admitted on April 26, 2025 for PTMC. The procedure was performed under local anesthesia and conscious sedation. Femoral venous access was obtained, and a transseptal puncture was performed to access the left atrium. The transseptal puncture was guided by fluoroscopy and confirmed by pressure monitoring. A multipurpose catheter was advanced across the mitral valve, and a guide wire was then maneuvered into the left ventricle. Subsequently, the Inoue balloon catheter was positioned across the valve. The balloon was inflated in a stepwise manner to a final diameter of 26 mm to achieve adequate leaflet separation. During the procedure, continuous hemodynamic monitoring was performed, and no significant complications such as cardiac tamponade or significant new-onset mitral regurgitation were observed. Post-procedural mitral regurgitation remained mild (grade 1+).

Immediate post-procedural echocardiographic assessment confirmed the success of the intervention. The MVA, as measured by 3D planimetry, increased from its pre-procedural value of 0.36 cm to 0.6 cm, and the PHT decreased to 158 ms (MVA 1.39 cm). The estimated systolic pulmonary artery pressure fell from 45 mmHg to 30 mmHg, and the tricuspid regurgitation gradient decreased from 40 mmHg to 25 mmHg. While a post-PTMC MVA of >1.5 cm is considered the benchmark for optimal success, this significant increase in MVA in a patient with a high Wilkins score is a very favorable outcome, as it is expected to alleviate the patient’s symptoms and improve his quality of life [7]. At discharge, the patient was in NYHA class II and reported marked symptom relief. The patient’s condition was stable throughout the procedure and hospital stay, and he was discharged on April 27, 2025 with instructions for follow-up. At one-month follow-up, the patient remained in NYHA class II, the MVA was stable at 0.6 cm, and no worsening of mitral regurgitation or pulmonary hypertension was observed (Fig. 1).

Fig. 1.

Comprehensive echocardiographic assessment before and after PTMC. A Pre-procedural apical four-chamber view with color Doppler showing severely restricted mitral inflow. B 3D en face view of the mitral valve from the left atrial perspective (multiplanar reconstruction) demonstrating severe commissural fusion, leaflet calcification, and a critically small orifice (planimetered area 0.36 cm). C Post-PTMC 3D view showing improved orifice area (0.6 cm) after commissural splitting. D Continuous-wave Doppler of mitral inflow before (PHT 280 ms) and after (PHT 158 ms) the procedure, reflecting hemodynamic improvement despite the challenging anatomy

Discussion

The successful outcome of this PTMC procedure, particularly in a patient with a high Wilkins score of 10 and a 3D echocardiographic score of 8, is an important clinical observation. It demonstrates that with careful Heart Team decision-making and expert procedural execution, PTMC can provide significant benefits even in patients with complex valvular anatomy. The high scores in our patient were primarily due to severe leaflet thickening, calcification, and commissural fusion, which are known to predict suboptimal results [8, 9]. The success in this case can be attributed to the operator’s experience and the controlled, stepwise inflation of the Inoue balloon, which allowed for gradual commissural splitting while minimizing the risk of leaflet tears and severe regurgitation [10].

The post-procedural MVA of 0.6 cm (by 3D planimetry), while not reaching the optimal threshold of 1.5 cm, represents a meaningful improvement from the initial critical state. The complementary PHT-derived MVA (1.39 cm) also confirms a significant hemodynamic gain. Crucially, the symptomatic improvement from NYHA class III to II and the sharp reduction in sPAP (45 to 30 mmHg) objectively demonstrate the clinical benefit. In patients with high Wilkins scores, it is more realistic to aim for a significant hemodynamic improvement rather than a large MVA increase; even a modest gain can reduce left atrial pressure and pulmonary hypertension [11, 12].

To the best of our knowledge, the baseline MVA of 0.36 cm is one of the lowest ever reported to be successfully treated with PTMC. Studies by Promratpan et al. and Kubota et al. have shown that PTMC in patients with Wilkins scores ≥ 8 yields a smaller final MVA and higher restenosis rates compared to those with favorable anatomy, yet many patients still experience symptomatic relief [8, 9]. Our case extends this observation to the extreme end of the spectrum, illustrating that a Heart-Team-guided, palliative PTMC can be a viable option when surgery is declined. The unique educational value lies in demonstrating that a high Wilkins score is not an absolute contraindication but mandates a comprehensive, individualized risk–benefit analysis incorporating 3D anatomic details, patient preference, and institutional expertise. Furthermore, comprehensive rehabilitation programs may contribute to improved functional outcomes after valvular interventions [13].

Long-term follow-up is essential for patients who have undergone PTMC, especially those with high Wilkins scores, as they are at higher risk for restenosis [14, 15]. Regular clinical and echocardiographic assessments at 6, 12, and 24 months are planned.

Conclusion

In a young patient with critical rheumatic mitral stenosis, a baseline MVA of 0.36 cm–one of the lowest reported—and a high Wilkins score of 10, PTMC guided by a multidisciplinary Heart Team resulted in a meaningful improvement in MVA, a significant reduction in pulmonary artery pressure, and objective symptomatic relief. This case underscores that, in selected patients with unfavorable anatomy who refuse surgery, PTMC can be a valuable palliative strategy when performed in an experienced center. The decision must be individualized, informed by advanced 3D echocardiographic characterization, and supported by a formal Heart Team evaluation, with patients counseled about the higher risk of restenosis and the possible need for future intervention.

Author contributions

Using initials to denote authors: M. H. M. (Mohammad Hadi Mansouri), M. H. J. (Mohammad Hashemi Jazi), B. N. (Bashir Najafabdian), A. T. (Aliakbar Tavassoli), R. Z. (Reihaneh Zavar), A. M. S. (Amir MirMohammad Sadeghi), M. B. (Mohaddeseh Behjati). M. B., M. H. M., and M. H. J. conceived and designed the case report and were responsible for clinical oversight. M. B. performed the PTMC procedure and led the echocardiographic acquisition and interpretation. B. N. prepared the technical and imaging figures, compiled procedural details, and drafted the initial manuscript. P. M. contributed to data analysis, literature review, and critical revision of the manuscript for important intellectual content. A. T. and R. Z. contributed to patient management, interpretation of clinical data, and manuscript review. A. M. S. provided surgical consultation, reviewed procedural safety considerations, and contributed to manuscript editing. All authors reviewed and revised the manuscript critically for important intellectual content, approved the final version for submission, and agree to be accountable for all aspects of the work. M. B. is the guarantor of the manuscript and serves as the corresponding author.

Funding

This study was conducted at Milad Hospital, Isfahan, and has no funding or declaration to report.

Data availability

No datasets were generated or analysed during the current study.

Declarations

Competing interests

The authors declare no competing interests.