Cardiogoniometry Compared to Fractional Flow Reserve at Identifying Physiologically Significant Coronary Stenosis: The CARDIOFLOW Study.

Cardiogoniometry (CGM) is method of 3-dimensional electrocardiographic assessment which has been shown to identify patients with angiographically defined, stable coronary artery disease (CAD). However, angiographic evidence of CAD, does not always correlate to physiologically significant disease. The aim of our study was to assess the ability of CGM to detect physiologically significant coronary stenosis defined by fractional flow reserve (FFR). In a tertiary cardiology centre, elective patients with single vessel CAD were enrolled into a prospective double blinded observational study. A baseline CGM recording was performed at rest. A second CGM recording was performed during the FFR procedure, at the time of adenosine induced maximal hyperaemia. A significant CGM result was defined as an automatically calculated ischaemia score < 0 and a significant FFR ratio was defined as < 0.80. Measures of diagnostic performance (including sensitivity and specificity) were calculated for CGM at rest and during maximal hyperaemia. Forty-five patients were included (aged 61.1 ± 11.0; 60.0% male), of which eighteen (40%) were found to have significant CAD when assessed by FFR. At rest, CGM yielded a sensitivity of 33.3% and specificity of 63.0%. At maximal hyperaemia the sensitivity and specificity of CGM was 71.4 and 50.0% respectively. The diagnostic performance of CGM to detect physiologically significant stable CAD is poor at rest. Although, the diagnostic performance of CGM improves substantially during maximal hyperaemia, it does not reach sufficient levels of accuracy to be used routinely in clinical practice.

Renal artery sympathetic denervation: observations from the UK experience.

BACKGROUND: Renal denervation (RDN) may lower blood pressure (BP); however, it is unclear whether medication changes may be confounding results. Furthermore, limited data exist on pattern of ambulatory blood pressure (ABP) response-particularly in those prescribed aldosterone antagonists at the time of RDN. METHODS: We examined all patients treated with RDN for treatment-resistant hypertension in 18 UK centres. RESULTS: Results from 253 patients treated with five technologies are shown. Pre-procedural mean office BP (OBP) was 185/102 mmHg (SD 26/19; n = 253) and mean daytime ABP was 170/98 mmHg (SD 22/16; n = 186). Median number of antihypertensive drugs was 5.0: 96 % ACEi/ARB; 86 % thiazide/loop diuretic and 55 % aldosterone antagonist. OBP, available in 90 % at 11 months follow-up, was 163/93 mmHg (reduction of 22/9 mmHg). ABP, available in 70 % at 8.5 months follow-up, was 158/91 mmHg (fall of 12/7 mmHg). Mean drug changes post RDN were: 0.36 drugs added, 0.91 withdrawn. Dose changes appeared neutral. Quartile analysis by starting ABP showed mean reductions in systolic ABP after RDN of: 0.4; 6.5; 14.5 and 22.1 mmHg, respectively (p < 0.001 for trend). Use of aldosterone antagonist did not predict response (p > 0.2). CONCLUSION: In 253 patients treated with RDN, office BP fell by 22/9 mmHg. Ambulatory BP fell by 12/7 mmHg, though little response was seen in the lowermost quartile of starting blood pressure. Fall in BP was not explained by medication changes and aldosterone antagonist use did not affect response.

Collateral donor artery physiology and the influence of a chronic total occlusion on fractional flow reserve.

BACKGROUND: The presence of a concomitant chronic total coronary occlusion (CTO) and a large collateral contribution might alter the fractional flow reserve (FFR) of an interrogated vessel, rendering the FFR unreliable at predicting ischemia should the CTO vessel be revascularized and potentially affecting the decision on optimal revascularization strategy. We tested the hypothesis that donor vessel FFR would significantly change after percutaneous coronary intervention of a concomitant CTO. METHODS AND RESULTS: In consecutive patients undergoing percutaneous coronary intervention of a CTO, coronary pressure and flow velocity were measured at baseline and hyperemia in proximal and distal segments of both nontarget vessels, before and after percutaneous coronary intervention. Hemodynamics including FFR, absolute coronary flow, and the coronary flow velocity-pressure gradient relation were calculated. After successful percutaneous coronary intervention in 34 of 46 patients, FFR in the predominant donor vessel increased from 0.782 to 0.810 (difference, 0.028 [0.012 to 0.044]; P=0.001). Mean decrease in baseline donor vessel absolute flow adjusted for rate pressure product: 177.5 to 139.9 mL/min (difference -37.6 [-62.6 to -12.6]; P=0.005), mean decrease in hyperemic flow: 306.5 to 272.9 mL/min (difference, -33.5 [-58.7 to -8.3]; P=0.011). Change in predominant donor vessel FFR correlated with angiographic (%) diameter stenosis severity (r=0.44; P=0.009) and was strongly related to stenosis severity measured by the coronary flow velocity-pressure gradient relation (r=0.69; P<0.001). CONCLUSIONS: Recanalization of a CTO results in a modest increase in the FFR of the predominant collateral donor vessel associated with a reduction in coronary flow. A larger increase in FFR is associated with greater coronary stenosis severity.

Cardiac MR imaging to measure myocardial blood flow response to the cold pressor test in healthy smokers and nonsmokers.

PURPOSE: To determine if myocardial perfusion cardiac magnetic resonance (MR) imaging can show changes in myocardial blood flow (MBF) during the cold pressor test (CPT) and can allow identification of the differing endothelial function of smokers and nonsmokers when compared during adenosine stress. MATERIALS AND METHODS: The study was approved by the institutional ethics review board and all participants gave informed written consent. Twenty-nine healthy volunteers (19 nonsmokers, 10 smokers; mean age ± standard deviation, 22 years ± 4) underwent 1.5-T MR imaging and analysis. Myocardial perfusion was assessed during rest, peak CPT, and adenosine hyperemia with a saturation-recovery gradient-echo pulse sequence (spatial resolution, 2.4 × 2.4 × 10 mm). Global, endocardial, and epicardial MBF were calculated by using Fermi-constrained deconvolution. Paired and independent t test statistical analyses were used to compare the responses between tests and groups. Regression analysis was performed to identify predictors of MBF change. RESULTS: MBF at rest was similar between the nonsmoking and smoking groups (0.97 mL/g/min ± 0.4 vs 0.96 mL/g/min ± 0.3, respectively; P = .96). Nonsmokers responded to CPT with a 47% increase in MBF (1.43 mL/g/min ± 0.5) and smokers responded with a 27% increase (1.22 mL/g/min ± 0.4; P < .001). An endocardial-to-epicardial gradient existed at rest (nonsmokers, 1.10 [P = .002]; smokers, 1.30 [P = .01]) and CPT (nonsmokers, 1.19 [P < .001] smokers, 1.28 [P = .04]) but reversed during adenosine stress (nonsmokers, 0.89 [P = .03]; smokers, 0.92 [P = .42]). CONCLUSION: Myocardial perfusion cardiac MR imaging during CPT can allow assessment of changes in MBF globally and in the separate myocardial layers in healthy smokers and nonsmokers. This allows the combined assessment of endothelium-dependent (CPT) and endothelium-independent (adenosine stress test) MBF reserve in a single study.

Reciprocal ECG change in reperfused ST-elevation myocardial infarction is associated with myocardial salvage and area at risk assessed by cardiovascular magnetic resonance.

OBJECTIVE: ST-elevation acute myocardial infarction (STEMI) is frequently associated with reciprocal ST depression in contralateral ECG leads. The relevance of these changes is debated. This study examined whether reciprocal ECG changes in STEMI reflect larger myocardial area at risk (AAR) and/or infarct size. DESIGN: Patients were stratified by presence of reciprocal change on the presenting ECG, defined as ≥ 1 mm ST depression in ≥ 2 inferior leads for anterior STEMI, or ≥ 2 anterior leads for inferior STEMI. Infarcted tissue was defined on late enhancement and AAR on T2-weighted cardiovascular magnetic resonance (CMR). SETTING: Patients with reperfused first STEMI underwent CMR within 3 days of presentation. MAIN OUTCOME MEASURES: In addition to AAR and infarct mass, myocardial salvage was calculated as (AAR mass-infarct mass) and salvage index as myocardial salvage/AAR mass. RESULTS: Thirty-five patients were analysed (n=35). Patients with reciprocal ECG changes (n=19) had higher AAR mass than those without (42 g vs 29 g, p<0.001), and higher myocardial salvage (27 g vs 9 g, p<0.001) and myocardial salvage index (61% vs 17%, p<0.001) but similar infarct size (16 g vs 20 g, p=0.3) and ejection fraction (43% vs 45%, p=0.5). CONCLUSIONS: STEMI patients with reciprocal ECG changes have larger AAR, higher myocardial salvage and salvage index than those without. Reciprocal changes appear to be a marker of increased ischaemic myocardium at risk and indicate the potential for increased salvage with emergency revascularisation. Reciprocal changes showed no relationship to infarct size, which may be influenced by ischaemia time and other treatment factors.

Assessment of valve haemodynamics, reverse ventricular remodelling and myocardial fibrosis following transcatheter aortic valve implantation compared to surgical aortic valve replacement: a cardiovascular magnetic resonance study.

OBJECTIVE: To compare the effects of transcatheter aortic valve implantation (TAVI) and surgical aortic valve replacement (SAVR) on aortic valve haemodynamics, ventricular reverse remodelling and myocardial fibrosis (MF) by cardiovascular magnetic resonance (CMR) imaging. DESIGN: A 1.5 T CMR scan was performed preoperatively and 6 months postoperatively. SETTING: University hospitals of Leeds and Leicester, UK. PATIENTS: 50 (25 TAVI, 25 SAVR; age 77±8 years) high-risk severe symptomatic aortic stenosis (AS) patients. MAIN OUTCOME MEASURES: Valve haemodynamics, ventricular volumes, ejection fraction (EF), mass and MF. RESULTS: Patients were matched for gender and AS severity but not for age (80±6 vs 73±7 years, p=0.001) or EuroSCORE (22±14 vs. 7±3, p<0.001). Aortic valve mean pressure gradient decreased to a greater degree post-TAVI compared to SAVR (21±8 mm Hg vs. 35±13 mm Hg, p=0.017). Aortic regurgitation reduced by 8% in both groups, only reaching statistical significance for TAVI (p=0.003). TAVI and SAVR improved (p<0.05) left ventricular (LV) end-systolic volumes (46±18 ml/m2 vs. 41±17 ml/m2; 44±22 ml/m2 vs. 32±6 ml/m2 and mass (83±20 g/m2 vs. 65±15 g/m2; 74±11 g/m2 vs. 59±8 g/m2). SAVR reduced end-diastolic volumes (92±19 ml/m2 vs. 74±12 ml/m2, p<0.001) and TAVI increased EF (52±12% vs. 56±10%, p=0.01). MF reduced post-TAVI (10.9±6% vs. 8.5±5%, p=0.03) but not post-SAVR (4.2±2% vs. 4.1±2%, p=0.98). Myocardial scar (p≤0.01) and baseline ventricular volumes (p<0.001) were the major predictors of reverse remodelling. CONCLUSIONS: TAVI was comparable to SAVR at LV reverse remodelling and superior at reducing the valvular pressure gradient and MF. Future work should assess the prognostic importance of reverse remodelling and fibrosis post-TAVI to aid patient selection.

The effect of microvascular obstruction and intramyocardial hemorrhage on contractile recovery in reperfused myocardial infarction: insights from cardiovascular magnetic resonance.

BACKGROUND: Following acute myocardial infarction (AMI), microvascular obstruction (MO) and intramyocardial hemorrhage (IMH) adversely affect left ventricular remodeling and prognosis independently of infarct size. Whether this is due to infarct zone remodeling, changes in remote myocardium or other factors is unknown. We investigated the role of MO and IMH in recovery of contractility in infarct and remote myocardium. METHODS: Thirty-nine patients underwent cardiovascular magnetic resonance (CMR) with T2-weighted and T2* imaging, late gadolinium enhancement (LGE) and myocardial tagging at 2, 7, 30 and 90 days following primary percutaneous coronary intervention for AMI. Circumferential strain in infarct and remote zones was stratified by presence of MO and IMH. RESULTS: Overall, infarct zone strain recovered with time (p < 0.001). In the presence of MO with IMH and without IMH, epicardial strain recovered (p = 0.03, p < 0.01 respectively), but mid-myocardial or endocardial strain did not (mid-myocardium: p = 0.05, p = 0.12; endocardium: p = 0.27, p = 0.05, respectively). By day 90, infarcts with MO had more attenuated strain in all myocardial layers compared to infarcts without MO (p < 0.01); those with IMH were attenuated further (p < 0.01). Remote myocardial strain was similar across groups at all time-points (p > 0.2). Infarct transmural extent did not correlate with strain (p > 0.05 at each time point). In multivariable logistic regression, MO and IMH were the only significant independent predictors of attenuated 90-day infarct zone strain (p = 0.004, p = 0.011, respectively). CONCLUSIONS: Strain improves within the infarct zone overall following reperfusion with or without MO or IMH. Mid-myocardial and endocardial infarct contractility is diminished in the presence of MO, and further in the presence of IMH. MO and IMH are greater independent predictors of infarct zone contractile recovery than infarct volume or transmural extent.

The cost-effectiveness of transcatheter aortic valve implantation versus surgical aortic valve replacement in patients with severe aortic stenosis at high operative risk.

OBJECTIVE: To determine the cost-effectiveness of transcatheter aortic valve implantation (TAVI) compared with surgical aortic valve replacement (SAVR) in a high-risk aortic stenosis (AS) population. DESIGN: A cost-utility analysis employing the National Institute of Clinical Excellence (NICE) reference case design for technology appraisals. SETTING: The perspective of the UK National Health Service. PATIENTS: Utility data from a UK high-risk AS population. TAVI and SAVR effectiveness was taken from the PARTNER A randomised controlled trial. MAIN OUTCOME MEASURES: Costs modelled over a 10 year horizon using a Markov model. Incremental cost-effectiveness ratios and cost-effectiveness acceptability curve were calculated with reference to the NICE willingness to pay per quality adjusted life year (QALY) gain threshold. Deterministic and probabilistic sensitivity analyses performed. RESULTS: Despite greater procedural costs (£16 500 vs £9,256), TAVI was cost-effective compared with SAVR over the 10 year model horizon (costs £52 593 vs £53 943 and QALYs 2.81 vs 2.75), indicating that TAVI dominated SAVR. This appeared to be due to greater postsurgical costs, related to the length and cost of hospital stay. The results appeared robust to a number of deterministic sensitivity and probabilistic analyses. The cost-effectiveness acceptability curve indicated that at the NICE £20 000 willingness to pay threshold per QALY gained, TAVI had a 64.6% likelihood of being cost-effective, compared with 35.4% for SAVR. CONCLUSIONS: TAVI is likely to be a cost-effective treatment for high-risk patients with AS compared with the reference standard of SAVR. However, uncertainty surrounding the long-term outcomes for TAVI patients remains; this could have a substantive impact on estimates of cost-effectiveness.

Relationship between myocardial edema and regional myocardial function after reperfused acute myocardial infarction: an MR imaging study.

PURPOSE: To compare the relationship of myocardial edema and corresponding contractile function over time in patients with reperfused acute myocardial infarction (AMI). MATERIALS AND METHODS: This study was approved by the regional ethics committee; all patients gave written informed consent. Thirty-nine patients (34 men; mean age, 57 years; age range, 35-73 years) underwent T2-weighted, tagging, and late gadolinium enhancement magnetic resonance imaging at three time points after primary percutaneous coronary intervention for ST-elevation AMI. Circumferential strain, T2-weighted signal intensity, and volume of infarct zones, peri-infarct zones, and remote myocardium were measured. Patients were stratified by presence or absence of peri-infarct edema, defined as areas with T2-weighted signal intensity of two or more standard deviations above that of remote myocardium. Statistical analysis was performed with repeated-measures analysis of variance with post hoc Bonferroni correction. RESULTS: Edematous peri-infarct myocardium had attenuated strain compared with remote myocardium at day 2 (-0.137 vs -0.226, P < .001), day 30 (-0.188 vs -0.240, P < .01), and day 90 (-0.207 vs -0.241, P = .01). Nonedematous peri-infarct myocardium had similar (P > .05) strain to remote myocardium at all time points. Strain improved in edematous peri-infarct myocardium at day 30 (P = .02) and day 90 (P < .01), closely mirroring resolution of intensity and volume of edema. Decreased strain correlated with edema volume (r = 0.30, P = .01) and normalized edema signal intensity (r = 0.28, P < .01). In eight patients with fully transmural infarction, infarct zone strain improved between day 2 and day 90 (P = .02). CONCLUSION: Improvement of strain in peri-infarct myocardium closely follows regression of myocardial edema. Volume of edema and intensity of signal on T2-weighted images relate to functional recovery after reperfused AMI.

Relationship of cardiac biomarkers and reversible and irreversible myocardial injury following acute myocardial infarction as determined by cardiovascular magnetic resonance.

BACKGROUND: Cardiovascular magnetic resonance (CMR) can accurately depict myocardial oedema, haemorrhage, infarction and microvascular obstruction. The purpose of this study was to establish the relationships between cardiac biomarkers and reversible and irreversible myocardial injury following AMI, as determined by CMR. METHODS: Forty-eight patients admitted with AMI and successfully treated with primary percutaneous coronary intervention were studied. A comprehensive CMR protocol was performed at day 2, 1 week, 1 month and 3 months after presentation. Blood samples were taken at the same intervals and analysed for highly sensitive C-reactive protein (hs-CRP), Troponin I, N-terminal-pro-brain natriuretic peptide (NT-pro-BNP) and Heart-type fatty acid binding protein (H-FABP). The CMR end points were the extent of myocardial oedema, haemorrhage and infarction as well as left ventricular function and volumes. RESULTS: Multiple regression analyses demonstrated that hs-CRP on 'day 2' was the strongest independent predictor of left ventricular ejection fraction (LVEF) (p=0.007) and left ventricular end-systolic volume (LVESV) (p=0.002) at 3 months. Troponin I level on 'day 2' was the only independent predictor of infarct size (p=0.002) at 3 months. Patients with haemorrhagic infarctions had significantly higher biomarker levels at 'day 2'. NT-pro-BNP levels were significantly greater in patients with myocardial haemorrhage at all four time points. CONCLUSIONS: C-reactive protein measured two days after reperfusion was the strongest independent predictor of left ventricular remodelling at three months. Elevated biomarker levels in patients with haemorrhagic infarction suggest that reperfusion haemorrhage is a marker of more severe myocardial injury and may be associated with adverse ventricular remodelling.

Serial change in health-related quality of life over 1 year after transcatheter aortic valve implantation: predictors of health outcomes.

OBJECTIVES: The goal of this study was to assess serial changes in patient health-related quality of life (HRQOL) over time and identify predictors of patient benefit. BACKGROUND: Severe aortic stenosis reduces the length and quality of a patient's life. Transcatheter aortic valve implantation (TAVI) is superior to standard medical therapy and noninferior to surgical aortic valve replacement for 1-year mortality. HRQOL is an important outcome measure for which there is limited evidence in TAVI populations. METHODS: A total of 102 patients (mean age 80 ± 0.6 years; 49% male) undergoing TAVI consented to participate. Two HRQOL questionnaires-the social functioning (SF)-12v2 with physical component summaries (PCS) and mental component summaries (MCS) and the EQ-5D (with a visual analog scale [VAS])-were completed at baseline, 30 days, 6 months, and 1 year according to the recommendations of the Valve Academic Research Consortium. A SF-6D utility measure was calculated from the SF-12 survey. RESULTS: HRQOL significantly improved over 1 year (PCS p = 0.02; EQ-5D p = 0.02; VAS p = 0.01; SF-6D p = 0.03), becoming similar to age-adjusted U.S. population norms. The greatest change occurred from baseline to 30 days (p < 0.001), with further significant improvements to 6 months (p < 0.01). An insignificant decline occurred between 6 months and 1 year (p > 0.05), but a linear pattern of change remained for PCS, EQ-5D, and VAS (p < 0.05). Male sex (SF-6D p = 0.01) and increased operator experience (PCS, EQ-5D, and VAS p < 0.05) were independent predictors of a greater improvement in HRQOL. CONCLUSIONS: HRQOL significantly improved early after TAVI and was maintained out to 1 year. Patient factors, procedural complications, and operator experience are predictors of health benefit at 1 year.

Systolic versus diastolic acquisition in myocardial perfusion MR imaging.

PURPOSE: To compare myocardial blood flow (MBF) at systole and diastole and determine the diagnostic accuracy of both phases in patients suspected of having coronary artery disease (CAD). MATERIALS AND METHODS: The study was approved by the regional ethics committee, and all patients gave written informed consent. After coronary angiography, 40 patients (27 men; mean age, 64 years ± 8) underwent stress-rest perfusion magnetic resonance (MR) imaging at 1.5 T, with images aquired simultaneously at end systole and middiastole. Patients were classified as having CAD (stenosis .70%) or no significant CAD. In patients with CAD, myocardial segments were classified as stenosis-dependent (downstream of significant stenosis) or remote. MBF and myocardial perfusion reserve (MPR) were calculated for each segment, and mean values in each phase were compared with paired t tests. The diagnostic accuracy of each phase was determined with receiver operating characteristic (ROC) analysis. RESULTS: Twenty-one of the 40 patients (53%) had CAD. Resting MBF was similar in both phases for patients with and patients without CAD (P > .05). Stress MBF was greater in diastole than systole in normal, remote, and stenosis-dependent segments (3.75 mL/g/min ± 1.50 vs 3.15 mL/g/min ± 1.10, respectively, for normal segments; 2.75 mL/g/min ± 1.20 vs 2.38 mL/g/min ± 0.99, respectively, for remote segments; 2.49 mL/g/min ± 1.07 vs 2.23 mL/g/min ± 0.90, respectively, for stenosis-dependent segments; P <.01). MPR was greater in diastole than systole in all segment groups (P < .05). The diagnostic accuracies at diastole and systole were similar (area under the ROC curve = 0.79 and 0.82, respectively; P = .30). CONCLUSION: Myocardial perfusion MR estimates of stress MBF and MPR were greater in diastole than systole in patients with and patients without CAD. However, both phases had similar diagnostic accuracy. These observations may be relevant to other dynamic perfusion methods, including computed tomography and echocardiography.

Diffusion-weighted MRI determined cerebral embolic infarction following transcatheter aortic valve implantation: assessment of predictive risk factors and the relationship to subsequent health status.

BACKGROUND: 'Silent' cerebral infarction and stroke are complications of transcatheter aortic valve implantation (TAVI). OBJECTIVE: To assess the occurrence of cerebral infarction, identify predictive risk factors and examine the impact on patient health-related quality of life (HRQoL). METHODS: Cerebral diffusion weighted MRI of 31 patients with aortic stenosis undergoing CoreValve TAVI was carried out. HRQoL was assessed at baseline and at 30 days by SF-12v2 and EQ5D questionnaires. RESULTS: New cerebral infarcts occurred in 24/31 patients (77%) and stroke in 2 (6%). Stroke was associated with a greater number and volume of cerebral infarcts. Age (r=0.37, p=0.042), severity of atheroma (arch and descending aorta; r=0.91, p<0.001, r=0.69, p=0.001, respectively) and catheterisation time (r=0.45, p=0.02) were predictors of the number of new cerebral infarcts. HRQoL improved overall: SF-12v2 physical component summary increased significantly (32.4±6.2 vs 36.5±7.2; p=0.03) with no significant change in mental component summary (43.5±11.7 vs. 43.1±14.3; p=0.85). The EQ5D score and Visual Analogue Scale showed no significant change (0.56±0.26 vs. 0.59±0.31; p=0.70, and 54.2±19 vs. 58.2±24; p=0.43). CONCLUSION: Multiple small cerebral infarcts occurred in 77% of patients with TAVI. The majority of infarcts were 'silent' with clinical stroke being associated with a both higher infarct number and volume. Increased age and the severity of aortic arch atheroma were independent risk factors for the development of new cerebral infarcts. Overall HRQoL improved and there was no association between the number of new cerebral infarcts and altered health status.

Timing of cardiovascular MR imaging after acute myocardial infarction: effect on estimates of infarct characteristics and prediction of late ventricular remodeling.

PURPOSE: To define the evolution of infarct characteristics with cardiovascular magnetic resonance (MR) imaging and to assess which of the cardiovascular MR data acquired at day 2 or at 1 week after acute myocardial infarction (AMI), is the stronger predictor of infarct size and left ventricular (LV) function measured at 3 months. MATERIALS AND METHODS: The study protocol was reviewed and approved by the local research ethics committee, and written informed consent was obtained. Forty-eight patients with reperfused AMI underwent cine, T2-weighted, and late gadolinium enhancement cardiovascular MR imaging at days 2, 7, 30, and 90 after index presentation. Continuous data between times were compared by using paired t tests or one-way analysis of variance. Multiple linear regression analyses were used to predict linear end points. RESULTS: Infarct size and extent of myocardial edema decreased significantly between day 2 and 1 week: Mean scar as a percentage of LV mass and standard deviation (SD), respectively, were 27.2 and 13.9 versus 21.6 and 14.1 (P < .001), and myocardial edema as a percentage of LV mass and SD, respectively, were 37.9 and 15.2 versus 32.3 and 14.3 (P = .003). These changes were accompanied by a significant improvement in LV ejection fraction (LVEF): Mean percentage of LVEF and SD, respectively, were 41.7 and 9.6 versus 44.6 and 10.1 (P < .001). When comparing data acquired at day 2 and 1 week, only cardiovascular MR data acquired at 1 week were independent predictors of LVEF and infarct size at 3 months. CONCLUSION: LVEF, infarct size, and extent of myocardial edema changed significantly during the 1st week after AMI. Overall, cardiovascular MR measurements acquired after 1 week have greater predictive value for infarct size and LV function at 3 months than data acquired at day 2.

Reperfusion haemorrhage as determined by cardiovascular MRI is a predictor of adverse left ventricular remodelling and markers of late arrhythmic risk.

BACKGROUND: Interstitial haemorrhage due to reperfusion of severely ischaemic myocardium can be detected in vivo by T2-weighted (T2W) and T2* cardiovascular magnetic resonance (CMR). The clinical implications of myocardial haemorrhage following primary percutaneous coronary intervention (PPCI) remain undetermined. OBJECTIVES: To assess whether the presence of myocardial haemorrhage influences ventricular remodelling and risk of late ventricular arrhythmia following PPCI for acute myocardial infarction (AMI). METHODS: Forty-eight patients with first ST-elevation AMI, treated successfully with PPCI, underwent CMR at day 2 and 3 months. Left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV) and left ventricular ejection fraction (LVEF) were determined from cine-CMR, infarct size and microvascular obstruction (MVO) from gadolinium-enhanced images and area at risk (AAR) from T2W CMR. Myocardial haemorrhage was defined as hypointense signal within the AAR on both T2W and T2* images. All patients had a signal-averaged electrocardiogram at 3 months. RESULTS: 30/48 (63%) patients had MVO and 12 of these showed myocardial haemorrhage. Patients with haemorrhagic myocardial infarction (MI) had significantly larger LVEDV and LVESV, lower LVEF and larger infarcts than those with non-haemorrhagic MI at baseline and at 3 months. The presence of haemorrhage was an independent predictor of adverse remodelling defined as increased LVESV on follow-up (p = 0.001, OR 1.6) and prolonged filtered QRS (fQRS) on signal-averaged ECG at 3 months (p = 0.020, OR 1.176). CONCLUSIONS: Reperfusion haemorrhage following AMI is associated with larger infarct size, diminished myocardial salvage and lower LVEF. The presence of haemorrhage is the strongest independent predictor of adverse ventricular remodelling and is also associated with prolonged fQRS duration, which is a marker of arrhythmic risk.

Relationship of dysglycemia to acute myocardial infarct size and cardiovascular outcome as determined by cardiovascular magnetic resonance.

BACKGROUND: Improved outcomes for normoglycemic patients suffering acute myocardial infarction (AMI) over the last decade have not been matched by similar improvements in mortality for diabetic patients despite similar levels of baseline risk and appropriate medical therapy. Two of the major determinants of poor outcome following AMI are infarct size and left ventricular (LV) dysfunction. METHODS: Ninety-three patients with first AMI were studied. 22 patients had diabetes mellitus (DM) based on prior history or admission blood glucose ≥ 11.1 mmol/l. 13 patients had dysglycemia (admission blood glucose ≥ 7.8 mmol/l but < 11.1 mmol/l) and 58 patients had normoglycemia (admission blood glucose < 7.8 mmol/l). Patients underwent cardiac magnetic resonance (CMR) imaging at index presentation and median follow-up of 11 months. Cine imaging assessed LV function and late gadolinium contrast-enhanced imaging was used to quantify infarct size. Clinical outcome data were collected at 18 months median follow-up. RESULTS: Patients with dysglycemia and DM had larger infarct sizes by CMR than normoglycemic patients; at baseline percentage LV scar (mean (SD)) was 23.0% (10.9), 25.6% (12.9) and 15.8% (10.3) respectively (p = 0.001), and at 11 months percentage LV scar was 17.6% (8.9), 19.1% (9.6) and 12.4% (7.8) (p = 0.017). Patients with dysglycemia and DM also had lower event-free survival at 18 months (p = 0.005). CONCLUSIONS: Patients with dysglycemia or diabetes mellitus sustain larger infarct sizes than normoglycemic patients, as determined by CMR. This may, in part, account for their adverse prognosis following AMI.