A study to assess changes in myocardial perfusion after treatment with spinal cord stimulation and percutaneous myocardial laser revascularisation (PMR): data from a randomised trial.

Publication Information

Author(s): Khan SN, McNab DC, Sharples LD, Freeman CJ, Hardy I, Stone DL, Schofield PM.
Title: A study to assess changes in myocardial perfusion after treatment with spinal cord stimulation and percutaneous myocardial laser revascularisation (PMR): data from a randomised trial.
Journal: Trials
Volume, issue, pages: 9:9
Year: 2008
Full Text Link: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2266700/
PubMed Link: http://www.ncbi.nlm.nih.gov/pubmed/18304366

Study description

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.

Patient selection

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

Pain location

Trunk (visceral and ischemic): 68

Pain characteristics

Ischemic: 68

Indications (trial/implant)

Angina pectoris: 68

Screening trial

Stimulation

System implantation

Outcomes

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.

Outcomes: pain

Other beneficial outcomes

Biological complications

Infection: 0
IPG site pain requiring relocation: 5 (relocation?)

Device complications

Electrode migration and/or malposition: 1
Generator migration: 1

Stimulation side effects

Uncomfortable stimulation: 14 described as undesirable

Cost effectiveness

Faculty and staff

Physician training: Cardiology/cardiothoracic surgery
Facility location: UK
Facility type: Hospital (tertiary referral center)

Data extraction information