Cell therapy in reperfused acute myocardial infarction does not improve the recovery of perfusion in the infarcted myocardium: a cardiac MR imaging study.

PURPOSE: To investigate the effects of cell therapy on myocardial perfusion recovery after treatment of acute myocardial infarction (MI) with primary percutaneous coronary intervention (PCI). MATERIALS AND METHODS: In this HEBE trial substudy, which was approved by the institutional review board (trial registry number ISRCTN95796863), the authors assessed the effects of intracoronary infusion with bone marrow-derived mononuclear cells (BMMCs) or peripheral blood-derived mononuclear cells (PBMCs) on myocardial perfusion recovery by using cardiac magnetic resonance (MR) imaging after revascularization. In 152 patients with acute MI treated with PCI, cardiac MR imaging was performed after obtaining informed consent-before randomization to BMMC, PBMC, or standard therapy (control group)-and repeated at 4-month follow-up. Cardiac MR imaging consisted of cine, rest first-pass perfusion, and late gadolinium enhancement imaging. Perfusion was evaluated semiquantitatively with signal intensity-time curves by calculating the relative upslope (percentage signal intensity change). The relative upslope was calculated for the MI core, adjacent border zone, and remote myocardium. Perfusion differences among treatment groups or between baseline and follow-up were assessed with the Wilcoxon signed rank or Mann-Whitney U test. RESULTS: At baseline, myocardial perfusion differed between the MI core (median, 6.0%; interquartile range [IQR], 4.1%-8.0%), border zone (median, 8.4%; IQR, 6.4%-10.2%), and remote myocardium (median, 12.2%; IQR, 10.5%-15.9%) (P < .001 for all), with equal distribution among treatment groups. These interregional differences persisted at follow-up (P < .001 for all). No difference in perfusion recovery was found between the three treatment groups for any region. CONCLUSION: After revascularization of ST-elevation MI, cell therapy does not augment the recovery of resting perfusion in either the MI core or border zone.

A proinflammatory monocyte response is associated with myocardial injury and impaired functional outcome in patients with ST-segment elevation myocardial infarction: monocytes and myocardial infarction.

BACKGROUND: In patients with ST-segment elevation myocardial infarction (STEMI), the importance of a well-balanced inflammatory reaction has been recognized for years. Monocytes play essential roles in regulating inflammation. Hence, we investigated the association between inflammatory characteristics of monocytes and myocardial injury and functional outcome in patients with STEMI. METHODS: Using flow cytometry, the levels of classical (CD14(++)CD62L(+)) and nonclassical (CD14(+)CD62L(-)) monocytes were analyzed in peripheral blood in 58 patients with STEMI at a median of 5 days (4-6 days) after primary percutaneous coronary intervention. In addition, the monocytic expression of several surface molecules and formation of monocyte-platelet complexes were measured. All patients underwent cardiovascular magnetic resonance imaging at baseline and 4-month follow-up. RESULTS: At baseline, patients with high levels of classical monocytes had impaired left ventricular (LV) ejection fraction (P = .002), larger infarct size (P = .001), and, often, presence of microvascular obstruction (P = .003). At follow-up, high levels of classical monocytes were negatively associated with the regional systolic LV function independent of the transmural extent of infarction. In contrast, positive associations for the levels of nonclassical monocytes were observed. Finally, up-regulation of macrophage 1 by blood monocytes and increased formation of monocyte-platelet complexes were associated with enhanced myocardial injury at baseline and impaired LV function at follow-up. CONCLUSIONS: This study shows an association between a proinflammatory monocyte response, characterized by high levels of classical monocytes, and severe myocardial injury and poor functional outcome after STEMI. Future studies are required to investigate the biologic nature of this association and therapeutic implications.

Intracoronary infusion of mononuclear cells from bone marrow or peripheral blood compared with standard therapy in patients after acute myocardial infarction treated by primary percutaneous coronary intervention: results of the randomized controlled HEBE trial.

AIMS: Previous trials that investigated cell therapy as an adjunctive therapy after acute myocardial infarction (AMI) have shown conflicting results. We designed a randomized controlled trial to determine the effect of intracoronary infusion of mononuclear cells from bone marrow (BM) or peripheral blood in patients with AMI. METHODS AND RESULTS: In a multicentre trial, 200 patients with large first AMI treated with primary percutaneous coronary intervention were randomly assigned to either intracoronary infusion of mononuclear BM cells (n = 69), mononuclear peripheral blood cells (n = 66), or standard therapy (without placebo infusion) (n = 65). Mononuclear cells were delivered intracoronary between 3 and 8 days after AMI. Regional and global left ventricular myocardial function and volumes were assessed by magnetic resonance imaging before randomization and at 4 months, and clinical events were reported. The primary endpoint of the percentage of dysfunctional left ventricular segments that improved during follow-up did not differ significantly between either of the treatment groups and control: 38.6 ± 24.7% in the BM group, 36.8 ± 20.9% in the peripheral blood group, and 42.4 ± 18.7% in the control group (P = 0.33 and P = 0.14). Improvement of left ventricular ejection fraction was 3.8 ± 7.4% in the BM group, 4.2 ± 6.2% in the peripheral blood group when compared with 4.0 ± 5.8% in the control group (P = 0.94 and P = 0.90). Furthermore, the three groups did not differ significantly in changes in left ventricular volumes, mass, and infarct size and had similar rates of clinical events. CONCLUSION: Intracoronary infusion of mononuclear cells from BM or peripheral blood following AMI does not improve regional or global systolic myocardial function in the HEBE trial. REGISTRATION: The Netherlands Trial Register #NTR166 (www.trialregister.nl) and the International Standard Randomised Controlled Trial, #ISRCTN95796863 (http://isrctn.org).

Predictive value of tissue Doppler imaging for left ventricular ejection fraction, remodelling, and infarct size after percutaneous coronary intervention for acute myocardial infarction.

AIMS: To investigate in ST-elevation myocardial infarction (STEMI) patients the value of tissue Doppler imaging (TDI) for an early estimation of the extent of myocardial salvage, left ventricular (LV) remodelling, and residual LV ejection fraction (LVEF). METHODS AND RESULTS: In 50 STEMI patients hospitalized for primary percutaneous coronary intervention (PCI), we investigated whether TDI can predict LVEF, infarct size, and LV remodelling as measured by magnetic resonance imaging (MRI) at 4 months post-MI. TDI was assessed within 24 h after MI with colour-coded TDI. Systolic and diastolic velocities from the six basal myocardial segments derived from three standard apical windows were averaged as a measure of global longitudinal velocity (i.e. Sm-6 and Em-6/Am-6, respectively). Sm-6 was shown to be a significant predictor of LVEF at 4 months. In addition, Sm-6 was a significant predictor of infarct size. No significant correlations were found between Sm-6 and LV remodelling. In addition, Sm-6 appeared to be a valuable clinical tool for identification of patients with LVEF > 40% or LVEF < 40% with acceptable positive predictive values. CONCLUSION: Sm-6 is a significant predictor of post-MI LVEF and infarct size as measured by MRI. In contrast, TDI-derived velocities do not predict LV remodelling.

Evaluation of global left ventricular function assessment by dual-source computed tomography compared with MRI.

Left ventricular (LV) function assessment by dual-source computed tomography (DSCT) was compared with the reference standard method using magnetic resonance imaging (MRI). Accurate assessment of LV function is essential for the prediction of prognosis in cardiac disease. Thirty-four patients undergoing DSCT examination of the heart for various clinical indications underwent MRI after DSCT. Short-axis cine images were reconstructed from the DSCT datasets and were analyzed using a dedicated post-processing software-tool to generate global left ventricular function parameters. Five DSCT datasets were considered to be of insufficient image quality. DSCT showed a small overestimation of end-diastolic and end-systolic volumes of 11.0 ml and 3.5 ml, respectively. Myocardial mass assessed by DSCT showed an average underestimation of 0.2 g. DSCT showed a small overestimation of LV ejection fraction (LVEF) of 0.4%-point with a Bland-Altman interval of [-8.67 (0.40) 9.48]. Global LV functional parameters calculated from DSCT datasets acquired in daily clinical practice correlated well with MRI and may be considered interchangeable. However, visual assessment of the image quality of the short-axis cine slices should be performed to detect any artifacts in the DSCT data which could influence accuracy.

Predictive value of Q waves on the 12-lead electrocardiogram after reperfusion therapy for ST elevation myocardial infarction.

DESIGN: The data used for the present study were obtained as part of a clinical trial evaluating the effect of thrombus aspiration after primary percutaneous coronary intervention (PCI). SETTING: The study was conducted at a tertiary referral facility for primary PCI at a University Medical Center Groningen in The Netherlands. BACKGROUND: Prognosis after ST elevation myocardial infarction (STEMI) is strongly related to infarct size. METHODS: As part of a randomized clinical trial, the first electrocardiogram (ECG) after primary PCI for STEMI was analyzed for the incidence of Q waves (>0.1 mV) on the 12-lead ECG. Infarct size was measured as area under curve (AUC) of creatine kinase (CK) and CK-myocardial band (CK-MB). RESULTS AND CONCLUSION: Nine hundred thirty-three patients were included, the median number of Q waves on the postprocedural ECG was 3 (interquartile range, 1-4). The number of Q waves on the postprocedural ECG was an independent predictor of infarct size measured either as AUC of CK (P < .001) or AUC of CK-MB (P < .001) and was a significant predictor of mortality during follow-up of 14 months. In conclusion, the number of Q waves on the postprocedural 12-lead ECG after primary PCI for STEMI is a strong predictor of infarct size and long-term mortality.

Intracoronary infusion of autologous mononuclear bone marrow cells in patients with acute myocardial infarction treated with primary PCI: Pilot study of the multicenter HEBE trial.

OBJECTIVE: This study was a pilot trial to determine safety and feasibility of intracoronary infusion of mononuclear bone marrow cells (MBMC) in patients with acute myocardial infarction (MI). BACKGROUND: Studies reporting the effect of MBMC therapy on improvement of left ventricular (LV) function have shown variable results. The HEBE trial is a large multicenter, randomized trial that currently enrolls patients. Prior to this trial we performed a pilot study. METHODS: Twenty-six patients with a first acute MI were prospectively enrolled in eight centers. Bone marrow aspiration was performed at a median of 6 days after primary PCI (interquartile range, 5-7 days). MBMC were isolated by gradient centrifugation and were infused intracoronary the same day. All patients underwent magnetic resonance imaging before cell infusion and after 4 months. Clinical events were assessed up to 12 months. RESULTS: Within 10 hr after bone marrow aspiration, 246 +/- 133 x 10(6) MBMC were infused, of which 3.9 +/- 2.3 x 10(6) cells were CD34(+). In one patient, this procedure was complicated by local dissection. LV ejection fraction significantly increased from 45.0 +/- 6.3% to 47.2 +/- 6.5% (P = 0.03). Systolic wall thickening in dysfunctional segments at baseline improved with 0.9 +/- 0.7 mm (P < 0.001). Infarct size decreased 37% from 17.8 +/- 8.2 to 11.2 +/- 4.2 gram (P < 0.001). During 12-month follow-up, 3 additional revascularizations were performed and an ICD was implanted in one patient, 3 weeks after PCI. CONCLUSION: In patients with acute MI, intracoronary infusion of MBMC is safe in a multicenter setting. At 4-month follow-up, a modest increase in global and regional LV function was observed, with a concomitant decrease in infarct size.

The importance of left ventricular function for long-term outcome after primary percutaneous coronary intervention.

BACKGROUND: In the present study we sought to determine the long-term prognostic value of left ventricular ejection fraction (LVEF), assessed by planar radionuclide ventriculography (PRV), after ST-elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PPCI). METHODS: In total 925 patients underwent PRV for LVEF assessment after PPCI for myocardial infarction before discharge from the hospital. PRV was performed with a standard dose of 500 Mbq of 99mTc-pertechnetate. Average follow-up time was 2.5 years. RESULTS: Mean (+/- SD) age was 60 +/- 12 years. Mean (+/- SD) LVEF was 45.7 +/- 12.2 %. 1 year survival was 97.3 % and 3 year survival was 94.2 %. Killip class, multi vessel-disease, previous cardiovascular events, peak creatin kinase and its MB fraction, age and LVEF proved to be univariate predictors of mortality. When entered in a forward conditional Cox regression model age and LVEF were independent predictors of 1 and 3 year mortality. CONCLUSION: LVEF assessed by PRV is a powerful independent predictor of long term mortality after PPCI for STEMI.

Parallel imaging for first-pass myocardial perfusion.

Two parallel imaging methods used for first-pass myocardial perfusion imaging were compared in terms of signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and image artifacts. One used adaptive Time-adaptive SENSitivity Encoding (TSENSE) and the other used GeneRalized Autocalibrating Partially Parallel Acquisition (GRAPPA), which are both applied to a gradient-echo sequence. Both methods were tested on 12 patients with coronary artery disease. The order of perfusion sequences was inverted in every other patient. Image acquisition was started during the administration of a contrast bolus followed by a 20-ml saline flush (3 ml/s), and the next perfusion was started at least 15 min thereafter using an identical bolus. An acceleration rate of 2 was used in both methods, and acquisition was performed during breath-holding. Significantly higher SNR, CNR and image quality were obtained with GRAPPA images than with TSENSE images. GRAPPA, however, did not yield a higher CNR when applied after the second bolus. GRAPPA perfusion imaging produced larger differences between subjects than did TSENSE. Compared to TSENSE, GRAPPA produced significantly better CNR on the first bolus. More consistent SNR and CNR were obtained from TSENSE images than from GRAPPA images, indicating that the diagnostic value of TSENSE may be better.

Intracoronary infusion of autologous mononuclear bone marrow cells or peripheral mononuclear blood cells after primary percutaneous coronary intervention: rationale and design of the HEBE trial--a prospective, multicenter, randomized trial.

BACKGROUND: Recently, several preliminary reports have demonstrated that cell transplantation after acute myocardial infarction in humans is safe and leads to better preserved left ventricular function and improved myocardial perfusion and coronary flow reserve. METHODS: The HEBE trial is a multicenter, prospective, randomized, 3-arm open trial with blinded evaluation of end points. Patients with acute large myocardial infarction treated with primary percutaneous coronary intervention (PCI) will undergo magnetic resonance imaging (MRI) and echocardiography. A total of 200 patients are randomized to treatment with (1) intracoronary infusion of autologous mononuclear bone marrow cells, (2) intracoronary infusion of peripheral mononuclear blood cells, or (3) standard therapy. Mononuclear cells are isolated from bone marrow aspirate or venous blood by density gradient centrifugation. Within 7 days after PCI and within 24 hours after bone marrow aspiration or blood collection, a catheterization for intracoronary infusion of the mononuclear cells in the infarct-related artery is performed. In all patients, follow-up will be obtained at 1, 4, and 12 months. MRI and catheterization are repeated at 4 months, and all images are analyzed by a core laboratory blinded to randomization. The primary end point of the study is the change in regional myocardial function in dysfunctional segments at 4 months relative to baseline, based on segmental analysis as measured by MRI. IMPLICATIONS: If intracoronary infusion of autologous mononuclear bone marrow cells or peripheral mononuclear blood cells is proven to be beneficial after primary PCI; it could be a valuable tool in preventing heart failure-related morbidity and mortality after myocardial infarction.

The feasibility of repeated left ventricular ejection fraction analysis with sequential single-dose radionuclide ventriculography.

OBJECTIVE: Repeated left ventricular ejection fraction (LVEF) analyses with sequential single-dose radionuclide ventriculography might be an interesting technique for monitoring the effect of positive inotropic interventions. The aim of the study was to assess the reproducibility of LVEF measurement with planar radionuclide ventriculography within 3 h, using a standard single dose of radioactive tracer. METHODS: Sixteen patients underwent routine planar radionuclide ventriculography with a standard dose of 500 MBq of [Tc]pertechnetate and returned after 3 h for a repeat planar radionuclide ventriculography without administration of additional tracer. RESULTS: The average initial LVEF was 35.1+/-18.6%-point (range, 12%-point to 68%-point). The mean difference of the LVEF between the initial planar radionuclide ventriculography and the repeat planar radionuclide ventriculography was 2.8%+/-6.3% (range, -11.8% to 13.3%, P=NS). The correlation between both measurements was significant with a correlation coefficient of 0.995 (P<0.01). Bland-Altman analysis revealed a mean LVEF difference of 0.94%-point between the baseline planar radionuclide ventriculography and the repeat planar radionuclide ventriculography (95% confidence interval: -2.7%-point to 4.5%-point). The visual wall motion assessment showed excellent reproducibility, with a kappa-statistic of 0.98. CONCLUSION: Repeated radionuclide ventriculography with a 3 h interval using a single standard dose of 500 MBq of [Tc]pertechnetate is highly reproducible and will be useful for monitoring the effect of positive inotropic interventions.

Long-term safety of intracoronary haemodynamic assessment for deferral of angioplasty in intermediate coronary stenoses: a 5-year follow-up.

BACKGROUND: Intracoronary flow and pressure measurements can be used for evaluating intermediate lesions. Studies focussing on short- and medium-term results demonstrated its safety. Long-term results are, however, not available. OBJECTIVE: The goal of this study was to assess the long-term safety and clinical implications of decision making for intermediate coronary stenosis based on intra-coronary haemodynamic measurements. METHODS AND RESULTS: In this prospective study, 61 patients with an intermediate coronary stenosis were included between January 1994 and December 1998. In these patients either coronary flow reserve or fractional flow reserve was measured. Death, target vessel revascularization, myocardial infarction, unstable angina and cerebrovascular accident were considered as major adverse cardiac events. The patients were followed during 5.5 (1.8) years for the occurrence of major adverse cardiac events (MACE). Although many patients presented with complaints, only 19.7% experienced a MACE in the follow-up period. CONCLUSION: Intracoronary measurements of CFR and FFR can be routinely used for objective clinical decision making in intermediate coronary stenoses. The low 5-year event rate supports conservative treatment strategy when cut-off values are implemented.

Long term outcome after mononuclear bone marrow or peripheral blood cells infusion after myocardial infarction.

OBJECTIVES: This study reports the long-term follow-up of the randomised controlled HEBE trial. The HEBE study is a multicentre trial that randomised 200 patients with large first acute myocardial infarction (AMI) treated with primary percutaneous coronary intervention to either intracoronary infusion of bone marrow mononuclear cells (BMMCs) (n=69), peripheral blood mononuclear cells (PBMCs) (n=66) or standard therapy (n=65). METHODS: In addition to 3-5 days, and 4 months after AMI, all patients underwent cardiac MRI after 2 years. A follow-up for 5 years after AMI was performed to assess clinical adverse events, including death, myocardial reinfarction and hospitalisation for heart failure. RESULTS: Of the 200 patients enrolled, 9 patients died and 12 patients were lost to follow-up at 5 years after AMI. BMMC group showed less increase in LV end-diastolic volume (LVEDV) (3.5±16.9 mL/m(2)) compared with (11.2±19.8 mL/m(2), p=0.03) in the control group, with no difference between the PBMC group (9.2±20.9 mL/m(2)) and controls (p=0.69). Moreover, the BMMC group showed a trend for decrease in LV end systolic volume (-1.8±15.0 mL/m(2)) as compared with controls (3.0±16.3 mL/m(2), p=0.07), with again no difference between PBMC (3.3±18.8 mL/m(2)) and controls (p=0.66). The combined endpoint of death and hospitalisation for heart failure was non-significantly less frequent in the BMMC group compared with the control group (n=4 vs n=1, p=0.20), with no difference between PBMC and controls (n=6 vs n=4, p=0.74). The composite endpoint of death or recurrent myocardial infarction was significantly higher in the PBMC group compared with controls (14 patients vs 3 patients, p=0.008), with no difference between the BMMC group and controls (2 vs 3 patients, p=0.67). CONCLUSIONS: Long-term follow-up of the HEBE trial showed that increase in LVEDV was lower in the BMMC group. This study supports the long-term safety of intracoronary BMMC therapy. However, major clinical cardiovascular adverse events were significantly more frequent in the PBMC group. TRIAL REGISTRATION NUMBER: The Netherlands Trial Register #NTR166 (http://www.trialregister.nl) and the International Standard Randomised Controlled Trial, #ISRCTN95796863 (http://isrctn.org).

Treatment synergy of silicon carbide-coated stenting and abciximab for complex coronary artery lesions: clinical results of a single-center study.

BACKGROUND: The aim of this study was to evaluate the combination of a silicon carbide-coated stent with the periprocedural use of abciximab in patients with type B2/C lesions. The study was a prospective cohort study and was conducted at the University Medical Center of Groningen. METHODS: Elective percutaneous transluminal coronary angioplasty was performed in a total of 44 patients. All had lesions with type B2/C characteristics and most were relatively small, tortuous and calcified. The involved vessel segment was stented. Silicon carbide-coated stents were used in combination with periprocedural abciximab. The main outcome measures were cardiac death, target vessel revascularization, myocardial infarction, and cerebrovascular accident. RESULTS: At 6 months of follow-up, only 4 patients had a major adverse cardiac event. Three patients had undergone target vessel revascularization and 1 patient had suffered from a cerebrovascular accident. Sixteen patients underwent re-angiography 6 months after the initial procedure. The average stenosis at 6 months was 15% with a minimal lumen diameter of 2.4 mm. CONCLUSIONS: A 9% major adverse cardiac event rate and a 7% target vessel revascularization rate at 6 months in type B2/C lesions were recorded. Further investigation on the use of this specific treatment combination is warranted.

Pathological Q waves in myocardial infarction in patients treated by primary PCI.

OBJECTIVES: In the present study, we investigated the association of pathological Q waves with infarct size. Furthermore, we investigated whether Q-wave regression was associated with improvement of left ventricular ejection fraction (LVEF), infarct size, and left ventricular dimensions in ST-segment elevation myocardial infarction (STEMI) patients with early Q-wave formation compared with patients without or persistent pathological Q waves. BACKGROUND: The criteria for pathological Q waves after acute myocardial infarction (MI) have changed over the years. Also, there are limited data regarding correlation of Q-wave regression and preservation of LVEF in patients with an initial Q-wave MI. METHODS: Standard 12-lead electrocardiograms (ECGs) were recorded in 184 STEMI patients treated with primary percutaneous coronary intervention (PCI). ECGs were recorded before and following PCI, as well as at 1, 4, 12, and 24 months of follow-up. An ECG was scored as Q-wave MI when it showed Q waves in 2 or more contiguous leads according to the 4 readily available clinical definitions used over the years: "classic" criteria, Thrombolysis In Myocardial Infarction criteria, and 2000 and 2007 consensus criteria. Cardiac magnetic resonance (CMR) examination was performed at 4 ± 2 days after reperfusion and repeated after 4 and 24 months. Contrast-enhanced CMR was performed at baseline and 4 months. RESULTS: The classic ECG criteria showed strongest correlation with infarct size as measured by CMR. The incidence of Q-wave MI according to the classic criteria was 23% 1 h after PCI. At 24 months of follow-up, 40% of patients with initial Q-wave MI displayed Q-wave regression. Patients with a Q-wave MI had larger infarct size and lower LVEF on baseline CMR (24 ± 10% LV mass and 37 ± 8%, respectively) compared with patients with non-Q-wave MI (17 ± 9% LV mass, p < 0.01, and 45 ± 8%, p < 0.001, respectively). Patients with Q-wave regression displayed significantly larger LVEF improvement in 24 months (9 ± 11%) as compared with both persistent Q-wave MI (2 ± 8%) as well as non-Q-wave MI (3 ± 8%, p = 0.04 for both comparisons). CONCLUSIONS: Association of Q waves with infarct size is strongest when using the classic Q-wave criteria. Q-wave regression is associated with the largest improvement of LVEF as assessed with CMR.

Myocardial infarct heterogeneity assessment by late gadolinium enhancement cardiovascular magnetic resonance imaging shows predictive value for ventricular arrhythmia development after acute myocardial infarction.

AIMS: The aim of this study was to assess the association between the proportions of penumbra-visualized by late gadolinium enhanced cardiovascular magnetic resonance imaging (LGE-CMR)-after acute myocardial infarction (AMI) and the prevalence of ventricular tachycardia (VT). METHODS: One-hundred and sixty-two AMI patients, successfully, treated by primary percutaneous coronary intervention (PCI) underwent LGE-CMR after a median of 3 days (3-4) and 24-h Holter monitoring after 1 month. With LGE-CMR, the total amount of enhanced myocardium was quantified and divided into an infarct core (>50% of maximal signal intensity) and penumbra (25-50% of maximal signal intensity). With Holter monitoring, the number of VTs (≥4 successive PVCs) per 24 h was measured. RESULTS: The mean total enhanced myocardium was 31 ± 11% of the left ventricular mass. The % penumbra accounted for 39 ± 11% of the total enhanced area. In 29 (18%) patients, Holter monitoring showed VT, with a median of 1 episode (1-3) in 24 h. A larger proportion of penumbra within the enhanced area increased the risk of VTs [OR: 1.06 (95% CI: 1.02-1.10), P = 0.003]. After multivariate logistic regression analysis, the presence of ventricular fibrillation before primary PCI [OR: 5.60 (95% CI: 1.54-20.29), P = 0.01] and the proportional amount of penumbra within the enhanced myocardium [OR: 1.06 (95% CI: 1.02-1.10), P = 0.04] were independently associated with VT on Holter monitoring. CONCLUSION: Larger proportions of penumbra in the subacute phase after AMI are associated with increased risk of developing VTs. Quantification of penumbra size may become a useful future tool for risk stratification and ultimately for the prevention of ventricular arrhythmias.

Value and limitations of electromechanical endocardial mapping in the assessment of global and regional left ventricular function and transmural extent of infarction: a comparison with cardiovascular magnetic resonance.

AIMS: To determine the relation between electromechanical endocardial mapping (EEM) and cardiac magnetic resonance (CMR) derived functional and viability parameters in patients with a large myocardial infarction. METHODS AND RESULTS: Forty-two patients with a large ST-elevation myocardial infarction underwent both EEM and CMR four months after primary percutaneous coronary intervention. EEM was performed to assess linear local shortening (LLS), unipolar voltage (UV) and bipolar voltage (BV). CMR cine imaging was performed to determine left ventricular global volumes, ejection fraction and regional function. Late gadolinium enhancement was used to assess size and transmural extent of infarction. Average LLS, UV and BV differed significantly between normal and dysfunctional segments (9.8 vs. 7.3, 11.8 vs. 9.7 and 3.3 vs. 2.8 for LLS, UV and BV respectively; p<0.001 for LLS and UV, p=0.006 for BV). In addition, average LLS, UV and BV, differed significantly between non-, subendocardial and transmural enhanced segments (10.8 vs. 8.8 vs. 5.0, 12.3 vs. 10.5 vs. 9.5 and 3.5 vs. 3.0 vs. 2.3 for LLS, UV and BV, respectively, p<0.001 for all variables). Although regional EEM data showed reasonable correlation with CMR, specific cut-off values for EEM parameters could not be established. CONCLUSIONS: EEM may be helpful in determining both the regional function and the transmural extent of infarction in patients with a large myocardial infarction. However, correlation with CMR parameters was moderate and exact cut-off values for EEM parameters could not be established. Further development of this potentially very useful modality is needed before it can be advocated for exact border-zone endocardial injection.

Early electrocardiographic findings and MR imaging-verified microvascular injury and myocardial infarct size.

OBJECTIVES: This study investigated early electrocardiographic findings in relation to left ventricular (LV) function, extent and size of infarction, and microvascular injury in patients with acute myocardial infarction (MI) treated with percutaneous coronary intervention (PCI). BACKGROUND: The electrocardiogram (ECG) is the most used and simplest clinical method to evaluate the risk for patients immediately after reperfusion therapy for acute MI. ST-segment resolution and residual ST-segment elevation have been used for prognosis in acute MI, whereas Q waves are related to outcome in chronic MI. We hypothesized that the combination of these electrocardiographic measures early after primary PCI would enhance risk stratification. METHODS: We prospectively included 180 patients with a first acute ST-segment elevation MI to assess ST-segment resolution, residual ST-segment elevation, and number of Q waves using the 12-lead ECG acquired on admission and 1 h after successful PCI. The ECG findings were related to LV function, infarction size and transmurality, and microvascular injury as assessed with cine and gadolinium-enhanced cardiac magnetic resonance 4 +/- 2 days after reperfusion therapy. RESULTS: Residual ST-segment elevation (beta = -2.00, p = 0.004) and the number of Q waves (beta = -1.66, p = 0.005) were independent ECG predictors of LV ejection fraction. Although the number of Q waves was the only independent predictor of infarct size (beta = 2.01, p < 0.001) and transmural extent of infarction (beta = 0.60, p < 0.001), residual ST-segment elevation was the only independent predictor of microvascular injury (odds ratio: 19.1, 95% confidence interval: 2.4 to 154, p = 0.005) in multivariable analyses. The ST-segment resolution was neither associated with LV function, infarct size, or transmurality indexes, nor with microvascular injury in multivariable analysis. CONCLUSIONS: In patients after successful coronary intervention for acute MI, residual ST-segment elevation and the number of Q waves on the post-procedural ECG offer valuable complementary information on prediction of myocardial function and necrosis and its microvascular status.

Left ventricular volume assessment by planar radionuclide ventriculography evaluated by MRI.

BACKGROUND: Assessment of left ventricular (LV) ejection fraction (LVEF) and LV volume are essential for the evaluation of prognosis in cardiac disease. LVEF and LV volumes can be measured with several imaging modalities, such as magnetic resonance imaging (MRI) or computed tomography; however, these are relatively expensive and time consuming. In contrast, planar radionuclide ventriculography (PRV) for LVEF assessment is a cost-effective, fast, and reliable technique, but PRV for LV volumes calculation is less common. AIM: Evaluation of a new hybrid geometrical count-based method (HGCBM) in comparison with two count-based methods (CBMs) and a geometrical method (GM) for the calculation of LV volumes with PRV using MRI as reference. METHODS: Thirty cardiac patients underwent routine PRV with a standard dose of 500 MBq of Tc-pertechnetate and additional cardiac MRI as reference method. LV volumes of PRV data were calculated by four different methods. The CBMs and GM are based on the assumption that the shape of the LV can be approximated by an ellipsoid or sphere, and the new HGCBM extracts the volume from the projected count rates themselves. RESULTS: All methods underestimated the LV volumes as compared with the MRI-measured volumes. The difference (mean+/-SD) of end-diastolic volume (EDV) between PRV and MRI was 33+/-23 ml for GM, 12+/-26 ml for HGCBM, 50+/-38 ml for CBM1, and 13+/-40 ml for CBM2. The correlation coefficients for EDV between PRV methods and MRI were r = 0.90 for GM and r = 0.85 for HGCBM. The CBMs showed poor correlation r = 0.64 with the MRI data and a high SD. The difference of end-systolic volume (ESV) between PRV and MRI was 23+/-19 ml for GM, 9+/-22 ml for HGCBM, 29+/-29 ml for CBM1, and 9+/-28 ml for CBM2. The correlation coefficients for ESV between PRV methods and MRI were r = 0.955 for GM and r = 0.914 for HGCBM, r = 0.85 for CBM1 and CBM2. Although GM showed a slightly higher correlation than HGCBM, the difference of EDV and ESV between PRV and MRI was much higher for GM in comparison with HGCBM. Both CBMs showed poor agreement with MRI data. CONCLUSION: PRV using the new HGCMB method in comparison with other methods is an easy and accurate method to determine LV volumes. However, all methods underestimate ESV and EDV slightly as compared with MRI.

Assessment of global left ventricular functional parameters: analysis of every second short-axis Magnetic Resonance Imaging slices is as accurate as analysis of consecutive slices.

The purpose of this study was to assess whether accurate global left-ventricular (LV) functional parameters can be obtained by analyzing every second short-axis magnetic resonance imaging cine series instead of consecutive slices, in order to reduce post-processing time. Forty patients, were scanned on a 1.5 T MRI-system (Magnetom Sonata, Siemens Medical Systems, Erlangen, Germany) using a steady-state free precession (SSFP) sequence. A stack of short-axis cine series from above the mitral valve through the apex was acquired. Post-processing was started at the most basal slice of the left ventricle, in which at least 50% of the circumference was myocardium. End-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF) and LV mass (LVM), were calculated. Data analysis was repeated, but now only every second slice was analyzed. Bland-Altman analysis showed slightly lower values for all LV parameters when only every second slice was analyzed, ranging from 1.7% difference for EF (limits of agreement -3.5 to 5.0) to 4.6% for SV (limits of agreement -7.2 to 15.0). Analysis of every second slice for quantification of global LV function is time-saving and as accurate as analysis of consecutive slices.