Images in cardiovascular medicine. Left ventricular electromechanical mapping of myocardial ischemia

Intramyocardial, autologous CD34+ cell therapy for refractory angina

RATIONALE

A growing number of patients with coronary disease have refractory angina. Preclinical and early-phase clinical data suggest that intramyocardial injection of autologous CD34+ cells can improve myocardial perfusion and function.

OBJECTIVE

Evaluate the safety and bioactivity of intramyocardial injections of autologous CD34+ cells in patients with refractory angina who have exhausted all other treatment options.

METHODS AND RESULTS

In this prospective, double-blind, randomized, phase II study (ClinicalTrials.gov identifier: NCT00300053), 167 patients with refractory angina received 1 of 2 doses (1×10(5) or 5×10(5) cells/kg) of mobilized autologous CD34+ cells or an equal volume of diluent (placebo). Treatment was distributed into 10 sites of ischemic, viable myocardium with a NOGA mapping injection catheter. The primary outcome measure was weekly angina frequency 6 months after treatment. Weekly angina frequency was significantly lower in the low-dose group than in placebo-treated patients at both 6 months (6.8±1.1 versus 10.9±1.2, P=0.020) and 12 months (6.3±1.2 versus 11.0±1.2, P=0.035); measurements in the high-dose group were also lower, but not significantly. Similarly, improvement in exercise tolerance was significantly greater in low-dose patients than in placebo-treated patients (6 months: 139±151 versus 69±122 seconds, P=0.014; 12 months: 140±171 versus 58±146 seconds, P=0.017) and greater, but not significantly, in the high-dose group. During cell mobilization and collection, 4.6% of patients had cardiac enzyme elevations consistent with non-ST segment elevation myocardial infarction. Mortality at 12 months was 5.4% in the placebo-treatment group with no deaths among cell-treated patients.

CONCLUSIONS

Patients with refractory angina who received intramyocardial injections of autologous CD34+ cells (10(5) cells/kg) experienced significant improvements in angina frequency and exercise tolerance. The cell-mobilization and -collection procedures were associated with cardiac enzyme elevations, which will be addressed in future studies.

Left ventricular electromechanical mapping: preliminary evidence of electromechanical changes after successful coronary intervention

BACKGROUND

Postinterventional ischemic myocardial dysfunction and its sequelae are still not well understood.

METHODS AND RESULTS

To gain further insight into the immediate physiologic consequences of coronary interventions and to better understand the nature of changes that result from such interventions, we analyzed 96 electromechanical maps from 48 patients before and after successful, uncomplicated percutaneous coronary interventions (PCI). A NOGA system was used to construct the map of the endocardial surface. Reproducibility was confirmed by constructing 10 additional maps in 5 patients who did not undergo an intervening procedure. Discordant areas were defined as those with preserved unipolar voltage (> or =7.5 mV) and diminished linear local shortening (< or =12.5%). On the basis of comparison of the variations in the discordance values (%) in the reproducibility group, patients were considered improved (lower values), worsened (higher values), or unchanged. In the reproducibility group, the mean variation in discordance was 2.18% +/- 1.26%, whereas in the PCI group, it was 21.97% +/- 18.47%. In the PCI group (rotational atherectomy subgroup [n = 10] and stent subgroup [n = 38]), left ventricular discordance values improved in 19 patients (39.6%), worsened in 24 (50%), and remained the same in 5 (10.4%). Of all variables analyzed, only abciximab was significantly associated with postintervention improvement in discordance (P =.02; odds ratio 0.165, 95% CI 0.03-0.88), regardless of the type of intervention performed (P =.61), whereas heparin alone was associated with more discordance after intervention (odds ratio 6.07, 95% CI 1.14-32.40).

CONCLUSIONS

We assessed the effect of percutaneous revascularization on myocardium by use of electromechanical data. For the first time, changes in linear local shortening in areas of preserved unipolar voltage were quantified, and worsening after successful Thrombolysis In Myocardial Infarction grade III coronary interventions was registered. The only variable associated with improvement on electromechanical data after interventions was the use of abciximab. This raises the question of the possible potential of this new diagnostic tool in assessing and quantifying postinterventional microvasculature pathological changes.