Gao 2007.

Study characteristics
Methods	RCT with parallel design
Participants	23 participants (15 as treatment group and 8 as a comparison group), Adults (> 18)
Interventions	Intervention: Transcoronary ablation of septal hypertrophy Control: Dual Chamber cardiac pacing
Outcomes	Ssymptoms improvement (NYHA classification, CCS classification) left ventricle outflow obstruction gradient (pressure gradient) New York Heart Association Functional Classification left ventricular wall thickness.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Authors mentioned that the patients "were randomised."
Allocation concealment (selection bias)	Unclear risk	No information given
Blinding (performance bias and detection bias) Self‐reported outcomes	Unclear risk	No information given
Blinding (performance bias and detection bias) Objective outcomes	Unclear risk	No information given
Incomplete outcome data (attrition bias) All outcomes	Low risk	2 drop‐outs in the treatment group, clearly reported
Selective reporting (reporting bias)	Low risk	All outcomes were reported
Other bias	Low risk	No other bias could be found