Acute Microvascular Impairment Post-Reperfused STEMI Is Reversible and Has Additional Clinical Predictive Value: A CMR OxAMI Study.

OBJECTIVES: This study sought to investigate the clinical utility and the predictive relevance of absolute rest myocardial blood flow (MBF) by cardiac magnetic resonance (CMR) in acute myocardial infarction. BACKGROUND: Microvascular obstruction (MVO) remains one of the worst prognostic factors in patients with reperfused ST-segment elevation myocardial infarction (STEMI). Clinical trials have focused on cardioprotective strategies to maintain microvascular functionality, but there is a need for a noninvasive test to determine their efficacy. METHODS: A total of 64 STEMI patients post-primary percutaneous coronary intervention underwent 3-T CMR scans acutely and at 6 months (6M). The protocol included cine function, T2-weighted edema imaging, pre-contrast T1 mapping, rest first-pass perfusion, and late gadolinium enhancement imaging. Segmental MBF, corrected for rate pressure product (MBFcor), was quantified in remote, edematous, and infarcted myocardium. RESULTS: Acute MBFcor was significantly reduced in infarcted myocardium compared with remote MBF (MBFinfarct 0.76 ± 0.20 ml/min/g vs. MBFremote 1.02 ± 0.21 ml/min/g, p < 0.001), but it significantly increased at 6M (MBFinfarct 0.76 ± 0.20 ml/min/g acute vs. 0.85 ± 0.22 ml/min/g at 6M, p < 0.001). On a segmental basis, acute MBFcor had incremental prognostic value for infarct size at 6M (odds of no LGE at 6M increased by 1.4:1 [p < 0.001] for each 0.1 ml/min/g increase of acute MBFcor) and functional recovery (odds of wall thickening >45% at 6M increased by 1.38:1 [p < 0.001] for each 0.1 ml/min/g increase of acute MBFcor). In subjects with coronary flow reserve >2 or index of myocardial resistance <40, acute MBF was associated with long-term functional recovery and was an independent predictor of infarct size reduction. CONCLUSIONS: Acute MBF by CMR could represent a novel quantitative imaging biomarker of microvascular reversibility, and it could be used to identify patients who may benefit from more intensive or novel therapies.

Massive mitral annular calcification mimicking intracardiac mass: Multimodality approach to diagnosis.

The correct differential diagnosis of cardiac masses can be challenging and often carries important clinical implications. We present the case of a 78-year-old man with a cardiac mass of unclear etiology diagnosed on echocardiography. Using a multimodality approach with cardiac magnetic resonance and computed tomography, it was possible to define the real nature of the mass as composed of 2 voluminous calcifications of the mitral annulus.

CMR Native T1 Mapping Allows Differentiation of Reversible Versus Irreversible Myocardial Damage in ST-Segment-Elevation Myocardial Infarction: An OxAMI Study (Oxford Acute Myocardial Infarction).

BACKGROUND: CMR T1 mapping is a quantitative imaging technique allowing the assessment of myocardial injury early after ST-segment-elevation myocardial infarction. We sought to investigate the ability of acute native T1 mapping to differentiate reversible and irreversible myocardial injury and its predictive value for left ventricular remodeling. METHODS AND RESULTS: Sixty ST-segment-elevation myocardial infarction patients underwent acute and 6-month 3T CMR, including cine, T2-weighted (T2W) imaging, native shortened modified look-locker inversion recovery T1 mapping, rest first pass perfusion, and late gadolinium enhancement. T1 cutoff values for oedematous versus necrotic myocardium were identified as 1251 ms and 1400 ms, respectively, with prediction accuracy of 96.7% (95% confidence interval, 82.8% to 99.9%). Using the proposed threshold of 1400 ms, the volume of irreversibly damaged tissue was in good agreement with the 6-month late gadolinium enhancement volume (r=0.99) and correlated strongly with the log area under the curve troponin (r=0.80) and strongly with 6-month ejection fraction (r=-0.73). Acute T1 values were a strong predictor of 6-month wall thickening compared with late gadolinium enhancement. CONCLUSIONS: Acute native shortened modified look-locker inversion recovery T1 mapping differentiates reversible and irreversible myocardial injury, and it is a strong predictor of left ventricular remodeling in ST-segment-elevation myocardial infarction. A single CMR acquisition of native T1 mapping could potentially represent a fast, safe, and accurate method for early stratification of acute patients in need of more aggressive treatment. Further confirmatory studies will be needed.

Helical distribution of hypertrophy in patients with hypertrophic cardiomyopathy: prevalence and clinical implications.

Recently a novel pattern of helical distribution of hypertrophy has been described in patients with hypertrophic cardiomyopathy (HCM). Our aim was to determine its prevalence and potential implications in an unselected cohort. One-hundred- and eight consecutive patients diagnosed with HCM by cardiac magnetic resonance (CMR) were included (median clinical follow up of 1718 days). All clinical and complementary test information was prospectively collected. The presence of a helical pattern was assessed by a simple measurement of the maximal left ventricle (LV) wall thickness (LVWT) for each of the 17 classical LV segments and it was classified in one of three types according to its extension. A helical distribution was detected in 58% of patients, and was associated to a higher incidence of left ventricular outflow tract obstruction (LVOT; 35% vs. 10%; p = 0.005) and systolic anterior motion of the mitral valve (SAM; 30% vs. 13%, p = 0.053). No significant difference in the maximal LVWT was observed. However, the presence of a helical pattern showed a significant association with non sustained ventricular tachycardia (NSVT; 22% vs. 7%; p = 0.029) and was associated to a higher risk of sudden cardiac death (SCD) calculated with the European society of cardiology (ESC) calculator (p = 0.006). Notably, patients with a more extense spiral had a higher incidence of heart failure (75% vs. 34%, p = 0.012) and all-cause death (21 vs. 3%, p = 0.049). A helical pattern is frequent in HCM and can be readily assessed on CMR standard cine sequences. In conclusion, a helical pattern carries negative clinical implications and is associated to a higher estimated risk of SCD.

Early gadolinium enhancement in hypertrophic cardiomyopathy: a potential premature marker of myocardial damage.

Early gadolinium enhancement (EGE), one CMR diagnostic criteria in acute myocarditis, has been related with hyperemia and capillary leakage. The value of EGE in hypertrophic cardiomyopathy (HCM) remains unknown. Our aim was to determine the prevalence of EGE in patients with HCM, and its relation with late gadolinium enhancement (LGE). The association of EGE with morphological and clinical parameters was also evaluated. Sixty consecutive patients with HCM and CMR from our center were included. All the clinical and complementary test information was collected prospectively in our HCM clinic. Left ventricular (LV) measurements were calculated from cine sequences. EGE and LGE were quantified with a dedicated software. Clinical events were collected from medical records. A slow wash-out pattern on EGE was detected in up to 68 % of the patients, being an isolated finding without LGE in 10 (16 %). This cohort showed a greater maximal LV wall thickness (20.1 ± 4 vs. 18.1 ± 3.5 mm, p = 0.010) and asymmetry ratio (1.86 ± 0.42 vs. 1.62 ± 0.46; p = 0.039). The percentage of EGE/slice and the difference with the percentage LGE/slice demonstrated a significant positive correlation with the maximal LV wall thickness (Rho 0.450 and 0.386 respectively). EGE also correlated with number of segments with LVH (LV hypertrophy) and the asymmetry ratio. Neither EGE nor LGE were associated with classical risk factors, the risk score for sudden cardiac death, or with major clinical events. EGE was a frequent finding in HCM, even in absence of LGE. This phenomenon showed a positive correlation with morphological markers of disease burden.

Proximal flow convergence method by three-dimensional color Doppler echocardiography for mitral valve area assessment in rheumatic mitral stenosis.

BACKGROUND: The two-dimensional (2D) proximal isovelocity surface area (PISA) method has important technical limitations for mitral valve orifice area (MVA) assessment in mitral stenosis (MS), mainly the geometric assumptions of PISA shape and the requirement of an angle correction factor. Single-beat real-time three-dimensional (3D) color Doppler imaging allows the direct measurement of PISA without geometric assumptions or the requirement of an angle correction factor. The aim of this study was to validate this method in patients with rheumatic MS. METHODS: Sixty-three consecutive patients with rheumatic MS were included. MVA was assessed using the transthoracic 2D and 3D PISA methods. Planimetry of MVA (2D and 3D) and the pressure half-time method were used as reference methods. RESULTS: The 3D PISA method had better correlations with the reference methods (with 2D planimetry, r = 0.85, P < .001; with 3D planimetry, r = 0.89, P < .001; and with pressure half-time, r = 0.85, P < .001) than the conventional 2D PISA method (with 2D planimetry, r = 0.63, P < .001; with 3D planimetry, r = 0.66, P < .001; and with pressure half-time, r = 0.68, P < .001). In addition, a consistent significant underestimation of MVA using the conventional 2D PISA method was observed. A high percentage (30%) of patients with nonsevere MS by 3D planimetry were misclassified by the 2D PISA method as having severe MS (effective regurgitant orifice area < 1 cm(2)). In contrast, the 3D PISA method had 94% agreement with 3D planimetry. Good intra- and interobserver agreement for 3D PISA measurements were observed, with intraclass correlation coefficients of 0.95 and 0.90, respectively. CONCLUSIONS: MVA assessment using PISA by single-beat real-time 3D color Doppler echocardiography is feasible in the clinical setting and more accurate than the conventional 2D PISA method.

Prognostic implications of atrio-ventricular block in patients undergoing primary coronary angioplasty in the stent era.

INTRODUCTION: Conduction disorders in patients with ST-segment elevation myocardial infarction (STEMI) are associated with high mortality. Previous studies have analyzed the implications of AVB in acute coronary syndrome treated with fibrinolysis. However, the implications of AVB in patients with STEMI treated with primary angioplasty have not been sufficiently studied. MATERIAL AND METHODS: 913 patients with STEMI treated with primary angioplasty. All clinical, electrocardiographic and angiographic variables were collected. RESULTS: AVB was documented in 115 patients (12.6%). On admission, AVB was present in 70 (7.7%), and persistent at hospital discharge in 36 (3.9 %). Within these, first-degree AVB was present in 29 (3.2%), second-degree in 27 (3%) and third-degree in 73 (8%). AVB was more frequent in women, elderly, hypertensive, diabetic, with worse functional class (Killip class > 2) and with higher incidence at inferior infarctions (P < 0.05). AVB in general and, more specifically, third-degree AVB was associated with a higher mortality (20.5% versus 5.7%; P < 0.001), re-infarction (8.2% versus 3.6%; P = 0.06) and a greater incidence of cardiogenic shock (33.3% versus 14%; P < 0.001). Interestingly, these events were more common in patients who had persistent AVB at hospital discharge than in those with transitory AVB or present at admission AVB. In the multivariate analysis, persistent AVB at hospital discharge proved to be an independent predictor of cardiovascular events (death and recurrent infarction), not the rest of AVB. CONCLUSIONS: AVB in patients who underwent primary angioplasty is associated with a worse prognosis while is in-hospital. This risk is particularly high in patients who had persistent AVB at hospital discharge.

Proximal isovelocity surface area by single-beat three-dimensional color Doppler echocardiography applied for tricuspid regurgitation quantification.

BACKGROUND: The two-dimensional (2D) proximal isovelocity surface area (PISA) method has known technical limitations, mainly the geometric assumptions of PISA shape required to calculate effective regurgitant orifice area (EROA). Recently developed single-beat real-time three-dimensional (3D) color Doppler imaging allows the direct measurement of PISA without geometric assumptions and has already been validated for mitral regurgitation assessment. The aim of this study was to apply this novel method in patients with chronic tricuspid regurgitation (TR). METHODS: Ninety patients with chronic TR were enrolled. EROA and regurgitant volume (Rvol) were assessed using transthoracic 2D and 3D PISA methods. Quantitative Doppler and 3D transthoracic planimetry of EROA were used as reference methods. RESULTS: Both EROA and Rvol assessed using the 3D PISA method had better correlations with the reference methods than using conventional 2D PISA, particularly in the assessment of eccentric jets. On the basis of 3D planimetry-derived EROA, 35 patients had severe TR (EROA ≥ 0.4 cm(2)). Among these 35 patients, 25.7% (n = 9) were underestimated as having nonsevere TR (EROA ≤ 0.4 cm(2)) using the 2D PISA method. In contrast, the 3D PISA method had 94.3% agreement (33 of 35) with 3D planimetry in classifying severe TR. Good intraobserver and interobserver agreement for 3D PISA measurements was observed, with intraclass correlation coefficients of 0.92 and 0.88 respectively. CONCLUSIONS: TR quantification using PISA by single-beat real-time 3D color Doppler echocardiography is feasible in the clinical setting and more accurate than the conventional 2D PISA method.

Prognosis of different types of atrial fibrillation in the primary angioplasty era.

BACKGROUND: Atrial fibrillation (AF) has been associated with a poor prognosis in patients with ST-segment elevation myocardial infarction. There is considerable controversy regarding the prognostic implications of different types of AF. METHODS AND RESULTS: We analyzed 913 patients consecutively admitted to our center with ST-segment elevation myocardial infarction undergoing a primary percutaneous coronary intervention. Clinical, ECG, and angiographic data were collected. We carried out univariate and multivariate analysis, using a combined endpoint of death, reinfarction, stroke, and clinically relevant bleeding. AF was documented in 117 patients. Among them, 25 presented AF at admission (previous AF) and 92 developed new-onset AF (66% transient, 13% persistent). Patients with AF were older, more frequently men, and had a worse Killip class, and a poorer left-ventricular ejection fraction. When analyzing the different types of AF, patients with new-onset AF (persistent and transient) had a higher Killip class and a worse left-ventricular ejection fraction. AF was associated with significantly higher in-hospital mortality and with a greater incidence of in-hospital adverse events. An increase in in-hospital mortality was recorded both for previous and for new-persistent AF, but after adjusting for confounding factors, only persistent AF was found to carry a worse short-term prognosis. CONCLUSION: In patients undergoing primary angioplasty in the stent era, AF is associated with a poor prognosis. This risk appears to be particularly high among patients with persistent AF.