Cardiovascular magnetic resonance characteristics and clinical outcomes of patients with ST-elevation myocardial infarction and no standard modifiable risk factors-A DANAMI-3 substudy.

Introduction: A higher 30-day mortality has been observed in patients with first-presentation ST elevation myocardial infarction (STEMI) who have no standard modifiable cardiovascular risk factors (SMuRFs), i. e., diabetes, hypertension, hyperlipidemia, and current smoker. In this study, we evaluate the clinical outcomes and CMR imaging characteristics of patients with and without SMuRFs who presented with first-presentation STEMI. Methods: Patients from the Third DANish Study of Acute Treatment of Patients With ST-Segment Elevation Myocardial Infarction (DANAMI-3) with first-presentation STEMI were classified into those with no SMuRFs vs. those with at least one SMuRF. Results: We identified 2,046 patients; 283 (14%) SMuRFless and 1,763 (86%) had >0 SMuRF. SMuRFless patients were older (66 vs. 61 years, p < 0.001) with more males (84 vs. 74%, p < 0.001), more likely to have left anterior descending artery (LAD) as the culprit artery (50 vs. 42%, p = 0.009), and poor pre-PCI (percutaneous coronary intervention) TIMI (thrombolysis in myocardial infarction) flow ≤1 (78 vs. 64%; p < 0.001). There was no difference in all-cause mortality, non-fatal reinfarction, or hospitalization for heart failure at 30 days or at long-term follow-up. CMR imaging was performed on 726 patients. SMuRFless patients had larger acute infarct size (17 vs. 13%, p = 0.04) and a smaller myocardial salvage index (42 vs. 50%, p = 0.02). These differences were attenuated when the higher LAD predominance and/or TIMI 0-1 flow were included in the model. Conclusion: Despite no difference in 30-day mortality, SMuRFless patients had a larger infarct size and a smaller myocardial salvage index following first-presentation STEMI. This association was mediated by a larger proportion of LAD culprits and poor TIMI flow pre-PCI. Clinical trial registration: clinicaltrials.gov, unique identifier: NCT01435408 (DANAMI 3-iPOST and DANAMI 3-DEFER) and NCT01960933 (DANAMI 3-PRIMULTI).

Angiographic outcome in patients treated with deferred stenting after ST-segment elevation myocardial infarction-results from DANAMI-3-DEFER.

AIMS: Stent implantation during primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI) occasionally results in flow disturbances and distal embolization, which may cause adverse clinical outcomes. Deferred stent implantation seems to reduce the impairment on myocardial function, although the mechanisms have not been clarified. We sought to evaluate whether deferred stenting could reduce flow disturbance in patients treated with primary PCI. METHODS AND RESULTS: Patients with STEMI included in the DANAMI-3-DEFER trial were randomized to deferred versus immediate stent implantation. The primary and secondary outcomes of this substudy were the incidences of slow/no reflow and distal embolization. A total of 1205 patients were included. Deferred stenting (n = 594) resulted in lower incidences of distal embolization [odds ratio (OR) 0.67, 95% confidence interval (CI) 0.46-0.98, P = 0.040] and slow/no reflow (OR 0.60, 95%CI 0.37-0.97, P = 0.039). In high-risk subgroups, the protective effect was greatest in patients >65 years of age (slow/no reflow: OR 0.36, 95% CI 0.17-0.72, P = 0.004 and distal embolization: OR 0.34, 95% CI 0.18-0.63, P = 0.001), in patients presenting with occluded culprit artery at admission (slow/no reflow: OR 0.33, 95% CI 0.16-0.65, P = 0.001 and distal embolization: OR 0.54, 95% CI 0.31-0.96, P = 0.036) and in patients with thrombus grade >3 (slow/no reflow: OR 0.37, 95% CI 0.20-0.67, P = 0.001 and distal embolization: OR 0.39, 95% CI 0.24-0.64, P < 0.001) with a significant P for interaction for all. CONCLUSION: Deferred stent implantation reduces the incidences of slow/no reflow and distal embolization, especially in older patients and in those with total coronary occlusion or high level of thrombus burden.

Ischemia From Nonculprit Stenoses Is Not Associated With Reduced Culprit Infarct Size in Patients with ST-Segment-Elevation Myocardial Infarction.

BACKGROUND: In patients with ST-segment-elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention, reperfusion injury accounts for a significant fraction of the final infarct size, which is directly related to patient prognosis. In animal studies, brief periods of ischemia in noninfarct-related (nonculprit) coronary arteries protect the culprit myocardium via remote ischemic preconditioning. Positive fractional flow reserve (FFR) documents functional significant coronary nonculprit stenosis, which may offer remote ischemic preconditioning of the culprit myocardium. The aim of the study was to investigate the association between functional significant, multivessel disease (MVD) and reduced culprit final infarct size or increased myocardial salvage (myocardial salvage index [MSI]) in a large contemporary cohort of STEMI patients. METHODS: Cardiac magnetic resonance was performed in 610 patients with STEMI at day 1 and 3 months after primary percutaneous coronary intervention. Patients were stratified into 3 groups according to FFR measurements in nonculprit stenosis (if any): angiographic single vessel disease (SVD), FFR nonsignificant MVD (functional SVD), or FFR-significant, functional MVD. RESULTS: A total of 431 (71%) patients had SVD, 35 (6%) had functional SVD, and 144 (23%) had functional MVD. There was no difference in final infarct size (mean infarct size [%left ventricular mass] SVD, 9±3%; functional SVD, 9±3%; and functional MVD, 9±3% [P=0.82]) or in MSI between groups (mean MSI [%left] SVD, 66±23%; functional SVD, 68±19%; and functional MVD, 69±19% [P=0.62]). In multivariable analyses, functional MVD was not associated with larger MSI (P=0.56) or smaller infarct size (P=0.55). CONCLUSIONS: Functional MVD in nonculprit myocardium was not associated with reduced culprit final infarct size or increased MSI following STEMI. This is important knowledge for future studies examining a cardioprotective treatment in patients with STEMI, as a possible confounding effect of FFR-significant, functional MVD can be discarded. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01435408 (DANAMI 3-iPOST and DANAMI 3-DEFER) and NCT01960933 (DANAMI 3-PRIMULTI).

Usefulness of High Sensitivity Troponin T to Predict Long-Term Left Ventricular Dysfunction After ST-Elevation Myocardial Infarction.

Guidelines recommend the use of transthoracic echocardiography (TTE) and clinical scores to risk stratify patients after ST-elevation myocardial infarction (STEMI). High sensitivity troponin T (hs-cTnT) is predictive of outcome after STEMI but the predictive value of hs-cTnT relative to other risk assessment tools has not been established. We aimed to compare the predictive value of hs-cTnT to other risk assessment tools in patients with STEMI. A subset of 578 patients with STEMI were included in this post-hoc study from the Third DANish Study of Optimal Acute Treatment of Patients with ST-segment Elevation Myocardial Infarction trial. Patients underwent cardiac magnetic resonance imaging (CMR) during index hospitalization as well as TTE at 1 year after their STEMI. The predictive value of hs-cTnT was compared with CKMB, infarct size (IS)/left ventricular ejection fraction (LVEF) assessed with CMR, LVEF assessed at discharge with TTE and the Global Registry of Acute Coronary Events (GRACE) and Thrombolysis in Myocardial Infarction (TIMI) risk-scores. The primary outcome was LV systolic dysfunction defined as LVEF ≤40% after 1 year on TTE. The area under the receiver operating characteristic curve analyses showed no significant difference between hs-cTnT and early CMR-assessed IS or LVEF in predicting subsequent LVEF ≤40%. Area under the curve for hs-cTnT was 0.82, 0.85 for IS (p = 0.22), and 0.87 for LVEF (p = 0.23). For predischarge TTE-assessed LVEF, the value was 0.85 (p = 0.45), 0.63 for creatine kinase-MB (p <0.001), 0.61 for the GRACE score (p <0.001), and 0.70 for the TIMI score (p = 0.02). A peak hs-cTnT value <3,500 ng/L ruled out LVEF ≤40% with probability of 98%. In conclusion, in patients presenting with STEMI undergoing PCI, hs-cTnT level strongly predicted long-term LV dysfunction and could be used as a clinical risk stratification tool to identify patients at high risk of progressing to LV dysfunction due to its general availability and high-predictive accuracy.

Impact of Multiple Myocardial Scars Detected by CMR in Patients Following STEMI.

OBJECTIVES: This study investigated the incidence and long-term prognostic importance of multiple myocardial scars in cardiac magnetic resonance (CMR) in a large contemporary cohort of patients with ST-segment elevation myocardial infarction (STEMI). BACKGROUND: Patients presenting with STEMI may have multiple infarctions/scars caused by multiple culprit lesions, previous myocardial infarction (MI) or procedure-related MI due to nonculprit interventions. However, the incidence, long-term prognosis, and distribution of causes of multiple myocardial scars remain unknown. METHODS: CMR was performed in 704 patients with STEMI 1 day after primary percutaneous coronary intervention (PCI) and again 3 months later. Myocardial scars were assessed by late gadolinium enhancement (LGE). T2-weighted technique was used to differentiate acute from chronic infarctions. The presence of multiple scars was defined as scars located in different coronary territories. The combined endpoints of all-cause mortality and hospitalization for heart failure were assessed at 39 months (interquartile range [IQR]: 31 to 48 months). RESULTS: At 3 months, 59 patients (8.4%) had multiple scars. Of these, multiple culprits in STEMI were detected in 7 patients (1%), and development of a second nonculprit scar at follow-up occurred in 10 patients (1.4%). The most frequent cause of multiple scars was a chronic scar in the nonculprit myocardium. The presence of multiple scars was independently associated with an increased risk of all-cause mortality and hospitalization for heart failure (hazard ratio: 2.7; 95% confidence interval: 1.1 to 6.8; p = 0.037). CONCLUSIONS: Multiple scars were present in 8.4% of patients with STEMI and were independently associated with an increased risk of long-term morbidity and mortality. The presence of multiple myocardial scars on CMR may serve as a useful tool in risk stratification of patients following STEMI. (DANish Study of Optimal Acute Treatment of Patients With ST-elevation Myocardial Infarction [DANAMI-3]; NCT01435408) (Primary PCI in Patients With ST-elevation Myocardial Infarction and Multivessel Disease: Treatment of Culprit Lesion Only or Complete Revascularization [PRIMULTI]; NCT01960933).

Importance of elevated heart rate in the very early phase of ST-segment elevation myocardial infarction: Results from the DANAMI-3 trial.

BACKGROUND: Elevated heart rate is associated with poor clinical outcome in patients with acute myocardial infarction. However, in patients with ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention the importance of elevated heart rate in the very early phase remains unknown. We evaluated the impact of elevated heart rate in the very early pre-hospital phase of ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention on cardiovascular magnetic resonance markers of reperfusion success and clinical outcome. METHODS: In this DANAMI-3 substudy, 1560 ST-segment elevation myocardial infarction patients in sinus rhythm without cardiogenic shock were included in the analyses of clinical outcome and 796 patients underwent cardiovascular magnetic resonance to evaluate area at risk, infarct size and left ventricular ejection fraction. Heart rate was assessed on the first electrocardiogram with ST-elevation (time of diagnosis). RESULTS: Despite equal area at risk (33%±11 versus 36%±16, p=0.174) patients with a pre-hospital heart rate ⩾100 beats per minute developed larger infarcts (19% (interquartile range, 9-17) versus 11% (interquartile range, 10-28), p=0.001) and a lower left ventricular ejection fraction (54%±12 versus 58%±9, p=0.047). Pre-hospital heart rate ⩾100 beats per minute was independently associated with an increased risk of all-cause mortality and heart failure (hazard ratio 2.39 (95% confidence interval 1.58-3.62), p<0.001). CONCLUSIONS: Very early heart rate ⩾100 beats per minute in ST-segment elevation myocardial infarction was independently associated with larger infarct size, reduced left ventricular ejection fraction and an increased risk of all-cause mortality and heart failure, and thus serves as an easily obtainable and powerful tool to identify ST-segment elevation myocardial infarction patients at high risk.

Deferred vs Immediate Stenting in Primary Percutaneous Coronary Intervention: A Collaborative Meta-analysis of Randomized Trials With Cardiac Magnetic Resonance Imaging Data.

BACKGROUND: The role of deferred vs immediate stenting during primary percutaneous coronary intervention (PCI) for patients with ST-segment elevation myocardial infarction (STEMI) remains controversial. METHODS: We undertook a collaborative meta-analysis of study-level data by searching electronic scientific databases for investigations of primary PCI patients randomized to deferred or immediate stenting and subsequent cardiac magnetic resonance imaging. Primary angiographic and imaging outcomes were slow/no-reflow and microvascular obstruction (MVO), respectively. Main secondary outcome was recurrent ischemia. RESULTS: Among 4 trials, a total of 1570 patients with STEMI were assigned to primary PCI with either deferred (n = 779) or immediate stenting (n = 791). Of these, 797 participants had analyzable cardiac magnetic resonance imaging examinations. Median clinical follow-up was 9 months. Patients treated with deferred stenting showed a lower risk of developing slow/no-reflow in the culprit vessel (risk ratio [RR], 0.54 [95% confidence interval (CI), 0.41-0.72]; P < 0.001), a similar risk for MVO (RR, 0.93 [95% CI, 0.76-1.14]; P = 0.51), and trended higher in the risk of recurrent ischemia (RR, 2.42 [95% CI, 0.88-6.63]; P = 0.09) compared with those treated with immediate stenting. The treatment effect for slow/no-reflow and MVO correlated with a thrombus score grade > 3 at the baseline angiography and with the total stent length implanted in the culprit artery. CONCLUSIONS: A strategy of deferred stenting during primary PCI improves angiographic but not imaging or clinical outcomes compared with immediate stenting. The potential lower risk for myocardial injury by deferred stenting in primary PCI patients with STEMI and high thrombus burden requires a confirmation in adequately sized randomized trials.

Benefit From Reperfusion With Primary Percutaneous Coronary Intervention Beyond 12 Hours of Symptom Duration in Patients With ST-Segment-Elevation Myocardial Infarction.

BACKGROUND: Guidelines recommend primary percutaneous coronary intervention (PCI) in patients with ST-segment-elevation myocardial infarction (STEMI) presenting ≥12 hours of symptom onset in the presence of ongoing ischemia. However, data supporting this recommendation are limited. We evaluated the effect of primary PCI on reperfusion success, using cardiac magnetic resonance, in STEMI patients with signs of ongoing ischemia presenting 12 to 72 hours after symptom onset compared with STEMI patients presenting <12 hours. METHODS AND RESULTS: We included 865 STEMI patients who underwent cardiac magnetic resonance just after index PCI and 3 months later. Despite equal area at risk (34±12% versus 33±12%; P=0.370), patients presenting late (n=58) had larger final infarct size (13% [interquartile range, 9-24] versus 11% [interquartile range, 4-19]; P=0.037) and smaller myocardial salvage index (0.58 [interquartile range, 0.39-0.71] versus 0.65 [interquartile range, 0.49-0.84]; P=0.021) compared with patients presenting <12 hours after symptom onset (n=807). However, 65% of late-presenting patients achieved substantial myocardial salvage ≥0.50, and area under the curve for symptom onset to PCI as predictor of a myocardial salvage index ≥0.50 was poor (0.58 [95% CI, 0.53-0.63]; P<0.001). In addition, final infarct size, salvage index and left ventricular function correlated weakly with duration from symptom onset to primary PCI ( R2 values <0.05). CONCLUSIONS: STEMI patients with signs of ongoing ischemia treated with primary PCI 12 to 72 hours after symptom onset had less myocardial salvage and developed larger infarcts. However, a large proportion achieved substantial myocardial salvage indicating a benefit from primary PCI in late-presenting patients. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifiers: NCT01435408 and NCT01960933.

Danegaptide for primary percutaneous coronary intervention in acute myocardial infarction patients: a phase 2 randomised clinical trial.

OBJECTIVES: Reperfusion immediately after reopening of the infarct-related artery in ST-segment elevation myocardial infarction (STEMI) may cause myocardial damage in addition to the ischaemic insult (reperfusion injury). The gap junction modulating peptide danegaptide has in animal models reduced this injury. We evaluated the effect of danegaptide on myocardial salvage in patients with STEMI. METHODS: In addition to primary percutaneous coronary intervention in STEMI patients with thrombolysis in myocardial infarction flow 0-1, single vessel disease and ischaemia time less than 6 hours, we tested, in a clinical proof-of-concept study, the therapeutic potential of danegaptide at two-dose levels. Primary outcome was myocardial salvage evaluated by cardiac MRI after 3 months. RESULTS: From November 2013 to August 2015, a total of 585 patients were randomly enrolled in the trial. Imaging criteria were fulfilled for 79 (high dose), 80 (low dose) and 84 (placebo) patients eligible for the per-protocol analysis. Danegaptide did not affect the myocardial salvage index (danegaptide high (63.9±14.9), danegaptide low (65.6±15.6) and control (66.7±11.7), P=0.40), final infarct size (danegaptide high (19.6±11.4 g), danegaptide low (18.6±9.6 g) and control (21.4±15.0 g), P=0.88) or left ventricular ejection fraction (danegaptide high (53.9%±9.5%), danegaptide low (52.7%±10.3%) and control (52.1%±10.9%), P=0.64). There was no difference between groups with regard to clinical outcome. CONCLUSIONS: Administration of danegaptide to patients with STEMI did not improve myocardial salvage. TRIAL REGISTRATION NUMBER: NCT01977755; Pre-results.

Factors Associated With and Outcomes After Ventricular Fibrillation Before and During Primary Angioplasty in Patients With ST-Segment Elevation Myocardial Infarction.

We aimed to assess the risk factors and outcome of ventricular fibrillation (VF) before and during primary percutaneous coronary intervention (PPCI) in patients with ST-segment elevation myocardial infarction. From 1999 to 2012, we consecutively enrolled 5,373 patients with ST-segment elevation myocardial infarction. In total, 410 of the patients had VF before and 88 had VF during PPCI. During a mean follow-up of 4.2 years, 1,196 subjects died. A logistic regression model identified younger age, anterior infarct, Killip class >I at admission, and a preprocedural Thrombolysis In Myocardial Infarction flow grade of 0 to I to be significantly associated with VF before PPCI, whereas inferior infarct, a preprocedural Thrombolysis In Myocardial Infarction flow grade of 0 to I, and Killip class >I at admission were significantly associated with VF during PPCI. All-cause mortality was evaluated using the Cox regression model. Compared with the patients without VF, those with VF before or during PPCI had a significantly increased 30-day mortality, with an adjusted hazard ratio = 3.40 (95% confidence interval 1.70 to 6.70) and 4.20 (95% confidence interval 1.30 to 13.30), respectively. Importantly, there was no tendency of 30-day mortality difference between VF before and during PPCI (p = 0.170). In patients with VF before or during PPCI who survived for at least 30 days, there was no increase in the long-term mortality. In conclusion, our data suggest that 30-day mortality is the same for patients with VF before PPCI compared with VF during PPCI, and the occurrence of VF before or during PPCI was associated with increased 30-day mortality but not with long-term mortality.

A mismatch index based on the difference between measured left ventricular ejection fraction and that estimated by infarct size at three months following reperfused acute myocardial infarction.

BACKGROUND AND AIM: The reduction of left ventricular ejection fraction (LVEF) following ST-segment elevation myocardial infarction (STEMI) is a result of infarcted myocardium and may involve dysfunctional but viable myocardium. An index that may quantitatively determine whether LVEF is reduced beyond the expected value when considering only infarct size (IS) has previously been presented based on cardiac magnetic resonance (CMR). The purpose of this study was to introduce the index based on the electrocardiogram (ECG) and compare indices based on ECG and CMR. METHOD AND RESULTS: In 55 patients ECG and CMR were obtained 3 months after STEMI treated with primary percutaneous coronary intervention. Significant, however moderate inverse relationships were found between measured LVEF and IS. Based on IS and LVEF an IS estimated LVEF was derived and an MI-LVEF mismatch index was calculated as the difference between measured LVEF and IS estimated LVEF. In 41 (74.5%) of the patients there was agreement between the ECG and CMR indices in regards to categorizing indices as >10 or ≤ 10 and generally no significant difference was detected, mean difference of 1.26 percentage points (p = 0.53). CONCLUSION: The study found an overall good agreement between MI-LVEF mismatch indices based on ECG and CMR. The MI-LVEF mismatch index may serve as a tool to identify patients with potentially reversible dysfunctional but viable myocardium, but future studies including both ECG and CMR are needed.

Termination of dobutamine infusion causes transient rebound left heart diastolic dysfunction in healthy elderly women but not in men: a cardiac magnetic resonance study.

Men and women are known to react differently to stress. Thus, stress cardiomyopathy almost solely strikes women. Stress cardiomyopathy is suggested to relate to sex differences in catecholamine reaction. Left heart function during dobutamine stress is well described, but sex-specific inotropic and lusitropic response to abrupt termination of dobutamine stress is not. We aimed to investigate sex differences in left ventricular (LV) and atrial (LA) function during and after dobutamine stress. We enrolled 20 healthy elderly subjects (60-70 yr, 10 females) and measured their LV and LA volumes throughout the cardiac cycle by cardiac magnetic resonance imaging at rest, during dobutamine stress (15 µg·kg(-1)·min(-1)), 15 min after termination (T15), and 30 min after termination (T30) of dobutamine stress. We calculated LV ejection fractions, LV stroke volumes, LV peak filling rates, and LA passive, active, and conduit volumes. Sex differences were not observed at rest or during dobutamine stress. Compared with prestress values, at T15 a rebound decrease in LV peak filling rate was observed in women (-22 ± 3%, P < 0.001) but not in men. This was reflected in reduced LA passive emptying volume (-40 ± 3%, P < 0.001) and a corresponding increase in LA active emptying volume (36 ± 2%, P < 0.001). At T30 there were no differences between the sexes. We conclude that dobutamine causes greater stress to the female heart. This is revealed after termination of dobutamine stress where the left heart recovers in men, whereas women experience rebound LV stiffening with reduced diastolic relaxation. This is the first report of a sex-specific transient rebound phenomenon in cardiovascular response to catecholamines.

Value of cardiac 320-multidetector computed tomography and cardiac magnetic resonance imaging for assessment of myocardial perfusion defects in patients with known chronic ischemic heart disease.

The challenge for therapies targeting perfusion abnormalities is to identify and evaluate the region of interest. The aim of this study was to compare rest and stress myocardial perfusion measured by cardiac multi-detector computed tomography (MDCT) and cardiac magnetic resonance (CMR) imaging in patients with invasive coronary angiography demonstrated occluded vessels. Twenty-four patients with refractory angina due to occluded coronary arteries underwent perfusion imaging obtained by 320-MDCT scanner and 1.5 T MR scanner. Rest and adenosine stress images were obtained and interpreted using the modified 17-segment American Heart Association model. For the qualitative analysis, each segment was graded according to the following scoring system: 0 = no defect, 1 = hypoperfusion transmural extent <1/3, 2 = 1/3-1/2, 3 = >1/2, and 4 = infarct stigmata. In the semiquantitative analysis the perfusion was either scored 0 (normal) or 1 (abnormal). The summed rest and stress scores were calculated. MDCT and CMR had a high probability to identify perfusion defects. An excellent correlation between MDCT and CMR summed rest (r = 0.916) and stress scores (r = 0.915) was found. The interobserver reproducibility was high for MDCT and CMR images. The qualitative and semiquantitative MDCT against CMR analysis of rest and stress images showed high concordance to detect perfusion defects per vascular territory and on a per myocardial segment basis. 320-MDCT and CMR perfusion imaging can be used clinically to identify myocardial perfusion defects and potentially evaluate the effect of therapy targeting perfusion abnormalities.

Deferred stent implantation in patients with ST-segment elevation myocardial infarction: a pilot study.

AIMS: Disturbance in the flow of an infarct-related artery due to embolisation of thrombus and plaque material occurs frequently during primary percutaneous coronary intervention (PCI) and is associated with impaired prognosis. The aim of the present study was to minimise the risk of embolisation during PCI in patients with ST-segment elevation myocardial infarction (STEMI). METHODS AND RESULTS: Of 124 consecutive patients with STEMI, thrombectomy and/or balloon dilatation was performed in 110 (89%). Stent implantation was deferred in 113 (91%) patients who then comprised the study group. In 38% of the patients stent implantation was deemed unnecessary at the second examination because of <30% residual stenosis and no visible thrombus, and all lesions re-examined three months later were patent. Major adverse cardiac events occurred in two patients during eight months of follow-up (one cardiac death, one case of reinfarction with target lesion revascularisation). In five patients no PCI was performed at all. Myocardial salvage determined by cardiac magnetic resonance in a subset of patients was relatively high. CONCLUSIONS: Deferred stent implantation is safe in the majority of patients with STEMI. Although the concept has to be evaluated in a randomised trial, the strategy may prove beneficial for many patients referred for primary PCI.

Left atrial volume and function in patients following ST elevation myocardial infarction and the association with clinical outcome: a cardiovascular magnetic resonance study.

AIMS: The left atrium (LA) transfers blood to the left ventricle in a complex manner. LA function is characterized by passive emptying (LA passive fraction), active emptying (LA ejection fraction), and total emptying (LA fractional change). Despite this complexity, the clinical relevance of the LA is based almost exclusively on LA maximal volume (LAmax), which may not glean the full prognostic potential. Cardiovascular magnetic resonance (CMR) is considered the most accurate method for studying LA function and size. The aim of the present study was to evaluate the prognostic importance of LA function in patients following ST elevation myocardial infarction (STEMI). METHODS AND RESULTS: In 199 patients, a CMR scan was performed within 1-3 days after STEMI to measure LAmax and minimal volume (LAmin) and LA function. The incidence of death, re-infarction, stroke, and admission for heart failure [major adverse cardiac event (MACE)] were registered during the follow-up period [2.3 years (inter-quartile range: 2.0-2.5)]. A total of 40 patients (20%) met the clinical endpoint of MACE during follow-up. In a Cox regression analysis adjusting for known risk factors, LA fractional change remained independently associated with MACE [adjusted hazard ratio: 0.66 (95% confidence interval: 0.46-0.95)]. LAmax, LAmin, or LA passive fraction was not independently associated with MACE. Furthermore, LA fractional change provided incremental prognostic value to LAmax and other known predictors (Wald χ(2) 31.0 vs. 39.9, P= 0.016). CONCLUSION: In STEMI patients, impaired LA fractional change is independently associated with outcome and provide incremental prognostic information to established predictors including LAmax.

Left atrial and ventricular function during dobutamine and glycopyrrolate stress in healthy young and elderly as evaluated by cardiac magnetic resonance.

The aim of this study is to describe phasic volume changes of the left atrium (LA) in healthy young and elderly subjects at rest and during pharmacological stress (PS). LA maximum size is related to cardiovascular mortality. LA has passive, active, and conduit function for left ventricular (LV) filling. We hypothesized that changes in LV compliance from normal aging are reflected in LA volume changes and that PS will augment these differences. We enrolled twenty young (20-30 yr) and twenty elderly (60-70 yr) healthy subjects and measured their LV and LA volumes by cardiac magnetic resonance imaging at rest and during dobutamine and glycopyrrolate stress. We identified LA minimum, maximum, and middiastolic volumes and the volume before atrial contraction. LA emptying volumes were calculated as LA passive and active emptying volumes and LA conduit volume. We also calculated LV peak filling rates (LVPFRs). Both at rest and during PS, LA maximum and minimum volumes were similar in the groups, whereas middiastolic volume was higher in the elderly. During PS, a marked decrease in LA passive emptying function and a corresponding increase in LA active emptying function were seen in the elderly but not in the young. At rest, LVPFR was lower in the elderly, and during PS this difference was augmented. The aging heart has reduced LVPFR, which is reflected in reduced LA passive and compensatory increased LA active volumetric contribution to LV stroke volume. These age-related differences are evident at rest and highly augmented during both dobutamine and glycopyrrolate stress.

Comparison of Selvester QRS score with magnetic resonance imaging measured infarct size in patients with ST elevation myocardial infarction.

BACKGROUND AND PURPOSE: Recent studies have shown that the Selvester QRS score is significantly correlated with delayed enhancement-magnetic resonance imaging (DE-MRI) measured myocardial infarct (MI) size in reperfused ST elevation MI (STEMI). This study further tests the hypothesis that Selvester QRS score correlates well with MI size determined by DE-MRI in reperfused STEMI. METHODS AND RESULTS: The relationship was evaluated retrospectively in 55 first-time STEMI patients 3 months after receiving primary percutaneous coronary intervention. Selvester QRS score and DE-MRI MI size were significantly correlated, r = 0.41 (P < .01). The difference between the Selvester QRS score and DE-MRI was 5.8% MI of the left ventricle (95% confidence interval, 2.9%-8.6%). Furthermore, increasing difference between Selvester QRS score and DE-MRI was observed with increasing MI size. CONCLUSION: Selvester QRS score correlated only moderately with DE-MRI MI size. Selvester QRS score overestimated MI size.