Study design:RCT (open-label, single-center, parallel group)
Study question:How does treatment with SCS versus PMR affect myocardial perfusion?
Population assessed:Human. Implanted SCS; treated with PMR.
Follow-up duration:12 months
Follow-up intervals:Baseline, 12 months
Other efforts to reduce bias:Perfusions analysis blinded.
Patient protection:Ethics committee, informed consent, Declaration of Helsinki
Outcome measures:Pre/post-treatment perfusion scans (rest and pharmacological stress) over 2 days. Technique is detailed.
Statistical significance:2-class Canadian Cardiovascular Society decrease
Statistical analyses performed:Perfusion assessed visually by blinded experienced personnel and scored 0-4. Stress and rest scores were summed and the differences calculated. Mantel-Haenszel test to compare Canadian Cardiovascular Society class; Fisher's exact test to compare proportion with significant improvement in each group; linear models with 95% CI used to determine treatment effect; asymmetrical results re-assessed for differences between baseline and 1 year against results of Mann-Whitney U tests.
Inclusion criteria:Canadian Cardiovascular Society class 3/4 refractory angina, conventional revascularization contraindicated (confirmed by imaging and 2 opinions), reversible ischemia on Tc-99m sestamibi scanning.
Exclusion criteria:Myocardial wall <8 mm thick in target area, cardiac implanted device, comorbidity more significant than angina.
Demographic / prognostic factors
Mean patient age in years (+/- SD, range):64.4 (+/- 7.5) SCS; 62.3 (+/- 9.7) PMR
Trunk (visceral and ischemic):68
Number in study:68 (randomized 34 SCS and 34 PMR)
Number followed:56 (28 SCS and 28 PMR)
Number lost to follow-up:12
Number with stimulation complication:17 (22 of 49 were SCS); 11 PMR (3 of 18 PRM-related, including 1 in pt randomized to SCS)
Answer to study question:No significant group difference in non-therapy related adverse events (although SCS patients had 26 vs. 16 PMR). '. . .no significance in perfusion between or within treatment groups at year one.' Recommend additional study with 'objective measures of myocardial performance [and] techniques other than myocardial perfusion imaging using adenosine as a stressor.'
Rate of success if defined:4 PMR and 9 SCS had 2-class and 2 SCS had 3-class improvement; no difference at 1 year in summed rest score, summed stress and summed difference 2.4 lower for SCS.
Data presented disaggregated and summarized?:For groups.
Other beneficial outcomes
IPG site pain requiring relocation:5 (relocation?)
Electrode migration and/or malposition:1
Stimulation side effects
Uncomfortable stimulation:14 described as undesirable
Faculty and staff
Physician training:Cardiology/cardiothoracic surgery
Facility type:Hospital (tertiary referral center)
Data extraction information
Submitted by/date submitted:JS Feb 2014