Comparison of outcomes of different balloon sets in patients undergoing percutaneous transvenous mitral commissurotomy

Abstract

Objective: To determine the outcomes of different balloon sets using in Percutaneous Transvenous Mitral Commissurotomy (PTMC) in symptomatic patients with moderate to severe Mitral Stenosis (MS). Background: Although Inoue balloon technique is commonly used worldwide but in our centre Bonhoeffer multi-track (double balloon) system is used for PTMC. It is, however, not known that which size of balloon set is more suitable in terms of favorable outcomes. Material and methods: This observational study was conducted at catheterization laboratory of tertiary care hospital at Karachi (Pakistan) from 1st January 2010 to 31st June 2011. A total of 203 consecutive patients were included in this study who were having Wilkins score of ≤8. Patients with more than mild mitral regurgitation (MR) and/or having clot in left atrium were excluded from the study. Selection of balloon size was on discretion of operator. However, 3 out of 4 operators used 14x14mm balloon set as a default balloon set. PTMC was considered successful in case of achieving mitral valve area (MVA) of ≥1.5 cm2 with no more than mild MR. Patients developing more than mild MR and valve area of <1.5 cm2 considered unsuccessful. Results: Out of 203 PTMC procedures, 14x14mm balloon set was used in 154 (75.8%) patients and 14x16mm in remaining 49 (24.1%) patients. 14x16mm balloon set was used in little bit aged (median age 33 versus 28 years; P=0.039) and taller patients (median height 156 versus 153 cm; P=0.010). Similarly, 14x16mm balloon set was more frequently used in patients with bigger annulus size (median annulus size 34 versus 33 mm; P=0.000) while the mitral valve area was same in both groups (median area 0.81 versus 0.81 cm2; P=0.061). Rest of the clinical, echo and cath features were also same in both groups. Post procedural analysis showed significantly greater achievement in valve area with 14x16mm balloon set (median valve area 3.24 versus 2.89 cm2; P=0.027). While trend towards lesser post procedural mean pressure gradient across mitral valve was observed with 14x16mm balloon set (median gradient 5 versus 6 mmHg; P=0.059). No significant difference in post procedure MR, tamponade and procedure failure was observed. However non-significant difference in success rate (87.7% with 14x16mm balloon set versus 77.9% with 14x14mm balloon set; P=0.153) was observed among the groups. Conclusion: Use of different size balloon set (14x16 mm) may be a better and safe strategy especially in taller and elder patients with bigger annulus size. However, further randomized studies in larger population are needed to validate our findings.