Pier Giorgio Masci

Myocardial fibrosis in isolated left ventricular non-compaction and its relation to disease severity.

The aim of the present study was to evaluate the prevalence and extent of myocardial fibrosis in patients with isolated left ventricular non‐compaction (LVNC) and to determine its relation to clinical status and LV systolic function.

Progression of Myocardial Fibrosis Assessed With Cardiac Magnetic Resonance in Hypertrophic Cardiomyopathy

OBJECTIVES This study sought to assess the rate of progression of fibrosis by 2 consecutive cardiac magnetic resonance (CMR) examinations and its relation with clinical variables. BACKGROUND In hypertrophic cardiomyopathy (HCM) myocardial fibrosis, detected by late gadolinium enhancement (LGE), is associated to a progressive ventricular dysfunction and worse prognosis. METHODS A total of 55 HCM patients (37 males; mean age 43 ± 18 years) underwent 2 CMR examinations (CMR-1 and CMR-2) separated by an interval of 719 ± 410 days. Extent of LGE was measured, and the rate of progression of LGE (LGE-rate) was calculated as the ratio between the increment of LGE (in grams) and the time (months) between the CMR examinations. RESULTS At CMR-1, LGE was detected in 45 subjects, with an extent of 13.3 ± 15.2 g. At CMR-2, 53 (96.4%) patients had LGE, with an extent of 24.6 ± 27.5 g. In 44 patients, LGE extent increased significantly (≥1 g). Patients with apical HCM had higher increments of LGE (p = 0.004) and LGE-rate (p < 0.001) than those with other patterns of hypertrophy. The extent of LGE at CMR-1 and the apical pattern of hypertrophy were independent predictors of the increment of LGE. Patients with worsened New York Heart Association functional class presented higher increase of LGE (p = 0.031) and LGE-rate (p < 0.05) than those with preserved functional status. CONCLUSIONS Myocardial fibrosis in HCM is a progressive and fast phenomenon. LGE increment, related to a worse clinical status, is more extensive in apical hypertrophy than in other patterns.

Myocardial Salvage by CMR Correlates With LV Remodeling and Early ST-Segment Resolution in Acute Myocardial Infarction

OBJECTIVES The purpose of this study was to assess the association of myocardial salvage by cardiac magnetic resonance (CMR) with left ventricular (LV) remodeling and early ST-segment resolution in patients with acute myocardial infarction (MI). BACKGROUND Experimental studies revealed that MI size is strongly influenced by the extent of the area at risk (AAR), limiting its accuracy as a marker of reperfusion treatment efficacy in acute MI studies. Hence, an index correcting MI size for AAR extent is warranted. T2-weighted CMR and delayed-enhancement CMR, respectively, enable the determination of AAR and MI size, and the myocardial salvage index (MSI) is calculated by correcting MI size for AAR extent. Nevertheless, the clinical value of CMR-derived MSI has not been evaluated yet. METHODS In a prospective cohort of 137 consecutive patients with acutely reperfused ST-segment elevation MI, CMR was performed at 1 week and 4 months. T2-weighted CMR was used to quantify AAR, whereas MI size was detected by delayed-enhancement imaging. MSI was defined as AAR extent minus MI size divided by AAR extent. Adverse LV remodeling was defined as an increase in LV end-systolic volume of >or=15%. The degree of ST-segment resolution 1 h after reperfusion was also calculated. RESULTS AAR extent was consistently larger than MI size (32+/-15% of LV vs. 18+/-13% of LV, p<0.0001), yielding an MSI of 0.46+/-0.24. MI size was closely related to AAR extent (r=0.81, p<0.0001). After correction for the main baseline characteristics by multivariate analyses, MSI was a major and independent determinant of adverse LV remodeling (odds ratio: 0.64; 95% confidence interval: 0.49 to 0.84, p=0.001) and was independently associated with early ST-segment resolution (B coefficient=0.61, p<0.0001). CONCLUSIONS In patients with reperfused ST-segment elevation MI, CMR-derived MSI is independently associated with adverse LV remodeling and early ST-segment resolution, opening new perspectives on its use in studies testing novel reperfusion strategies.

Relationship between location and size of myocardial infarction and their reciprocal influences on post-infarction left ventricular remodelling

AIMS To assess the intricate relationship between myocardial infarction (MI) location and size and their reciprocal influences on post-infarction left ventricular (LV) remodelling. METHODS AND RESULTS A cohort of 260 reperfused ST-segment elevation MI patients was prospectively studied with cardiovascular magnetic resonance at 1 week (baseline) and 4 months (follow-up). Area at risk (AAR) and MI size were quantified by T2-weighted and late-gadolinium enhancement imaging, respectively. Adverse LV remodelling was defined as an increase in LV end-systolic volume ≥15% at follow-up. One hundred and twenty-seven (49%) patients had anterior MI and 133 (51%) patients had non-anterior MI. Although the degree of myocardial salvage was similar between groups (P = 0.74), anterior MI patients had larger AAR and MI size than non-anterior MI patients yielding worse regional and global LV function at baseline and follow-up. At univariable analysis, anterior MI was associated with increased risk of adverse LV remodelling (P = 0.017) and lower LV ejection fraction (EF) at follow-up (P = 0.001), but not when accounted for baseline MI size. Accordingly, at multivariable analysis, baseline MI size but not its location was an independent predictor of adverse LV remodelling (odds ratio = 1.061, P < 0.001) and EF at follow-up (β-coefficient = -0.255, P < 0.001). CONCLUSION Anterior MI patients experience more pronounced post-infarction LV remodelling and dysfunction than non-anterior MI patients due to a greater magnitude of irreversible ischaemic LV damage without any independent contribution of MI location.

Right Ventricular Ischemic Injury in Patients With Acute ST-Segment Elevation Myocardial Infarction. Characterization With Cardiovascular Magnetic Resonance

Background— Experimental data show that the right ventricle (RV) is more resistant to ischemia than the left ventricle. To date, limited data are available in humans because of the difficulty of discriminating reversible from irreversible ischemic damage. We sought to characterize RV ischemic injury in patients with reperfused myocardial infarction using cardiovascular magnetic resonance. Methods and Results— In 3 tertiary centers, 242 consecutive patients with reperfused acute ST-segment elevation myocardial infarction were studied with cardiovascular magnetic resonance at 1 week and 4 months after myocardial infarction. T2-weighted and postcontrast cardiovascular magnetic resonance scans were used to depict myocardial edema and late gadolinium enhancement, respectively. Early after infarction, RV edema was common (51% of patients), often associated with late gadolinium enhancement (31% of patients). Remarkably, RV edema and late gadolinium enhancement were found in 33% and 12% of anterior left ventricular infarcts, respectively. Baseline regional and global RV functions were inversely related to the presence and extent of RV edema and RV late gadolinium enhancement. At follow-up, a significant decrease in frequency (25/242 patients; 10%) and extent of RV late gadolinium enhancement was observed (P<0.001). With the use of multivariable analysis, the presence of RV edema was an independent predictor of RV global function improvement during follow-up (&bgr;-coefficient=0.221, P=0.003). Conclusions— Early postinfarction RV ischemic injury is common and is characterized by the presence of myocardial edema, late gadolinium enhancement, and functional abnormalities. RV injury is not limited to inferior infarcts but is commonly found in anterior infarcts as well. Cardiovascular magnetic resonance findings suggest reversibility of acute RV dysfunction with limited permanent myocardial damage at 4-month follow-up.

Myocardial fibrosis as a key determinant of left ventricular remodeling in idiopathic dilated cardiomyopathy: a contrast-enhanced cardiovascular magnetic study

Background— In idiopathic dilated cardiomyopathy, there are scarce data on the influence of late gadolinium enhancement (LGE) assessed by cardiovascular magnetic resonance on left ventricular (LV) remodeling. Methods and Results— Fifty-eight consecutive patients with idiopathic dilated cardiomyopathy underwent baseline clinical, biohumoral, and instrumental workup. Medical therapy was optimized after study enrollment. Cardiovascular magnetic resonance was used to assess ventricular volumes, function, and LGE extent at baseline and 24-month follow-up. LV reverse remodeling (RR) was defined as an increase in LV ejection fraction ≥10 U, combined with a decrease in LV end-diastolic volume ≥10% at follow-up. &Dgr;LGE extent was the difference in LGE extent between follow-up and baseline. LV-RR was observed in 22 patients (38%). Multivariate regression analysis showed that the absence of LGE at baseline cardiovascular magnetic resonance was a strong predictor of LV-RR (odds ratio, 10.857 [95% confidence interval, 1.844–63.911]; P=0.008) after correction for age, heart rate, New York Heart Association class, LV volumes, and LV and right ventricular ejection fractions. All patients with baseline LGE (n=26; 45%) demonstrated LGE at follow-up, and no patient without baseline LGE developed LGE at follow-up. In LGE-positive patients, there was an increase in LGE extent over time (P=0.034), which was inversely related to LV ejection fraction variation (Spearman &rgr;, −0.440; P=0.041). Five patients showed an increase in LGE extent >75th percentile of &Dgr;LGE extent, and among these none experienced LV-RR and 4 had a decrease in LV ejection fraction ≥10 U at follow-up. Conclusions— In patients with idiopathic dilated cardiomyopathy, the absence of LGE at baseline is a strong independent predictor of LV-RR at 2-year follow-up, irrespective of the initial clinical status and the severity of ventricular dilatation and dysfunction. The increase in LGE extent during follow-up was associated with progressive LV dysfunction.

Incremental Prognostic Value of Myocardial Fibrosis in Patients With Non–Ischemic Cardiomyopathy Without Congestive Heart Failure

Background—We conducted a prospective longitudinal study to investigate the yet unknown clinical significance of myocardial fibrosis in patients with non–ischemic cardiomyopathy without history of congestive heart failure (CHF). Methods and Results—At 3 tertiary referral centers, 228 patients with non–ischemic cardiomyopathy without history of CHF were studied with cardiovascular magnetic resonance for late gadolinium enhancement (LGE) detection and quantification and prospectively followed up for a median of 23 months. The end point was a composite of cardiac death, onset of CHF, and aborted sudden cardiac death. LGE was detected in 61 (27%) patients. Thirty-one of 61 (51%) patients with LGE reached combined end point when compared with 18 of 167 (11%) patients without LGE (hazard ratio, 5.10 [2.78–9.36]; P<0.001). Patients with LGE had greater risk of developing CHF than patients without LGE (hazard ratio, 5.23 [2.61–10.50]; P<0.001) and higher rate of aborted sudden cardiac death (hazard ratio, 8.31 [1.66–41.55]; P=0.010). Multivariate analysis showed that LGE was associated with high likelihood of composite end point independent of other prognostic determinants, including age; duration of cardiomyopathy; and left ventricular volumes, mass, and ejection fraction (hazard ratio, 4.02 [2.08–7.76]; P<0.001). Improvement &khgr;2 analysis disclosed that LGE addition to models, including clinical data alone or in combination with parameters of left ventricular remodeling and function, yielded an improvement in outcome prediction (P<0.001). Addition of LGE to age and left ventricular ejection fraction improved risk stratification for composite end point (net reclassification improvement, 29.6%) and onset of CHF (net reclassification improvement, 25.4%; both P<0.001). Conclusions—In patients with non–ischemic cardiomyopathy without history of CHF, myocardial fibrosis is a strong and independent predictor of outcome, providing incremental prognostic information and improvement in risk stratification beyond clinical data and degree of left ventricular dysfunction.

Myocardial delayed enhancement in paucisymptomatic nonischemic dilated cardiomyopathy.

OBJECTIVES We investigated the prognostic role of myocardial fibrosis by delayed enhancement (DE) cardiovascular magnetic resonance (CMR) in nonischemic dilated cardiomyopathy (NICM) patients with no or mild symptoms of heart failure (HF). METHODS A prospective cohort of 125 NICM patients (82 males, age 59±14years, mean±SD) with echocardiographic evidence of left ventricular (LV) systolic dysfunction (mean ejection-fraction 33±10%), without (stage B) or with history of mild HF symptoms (stage C, NYHA classes I-II) was enrolled. The end-point was a composite of cardiac death and HF hospitalization. RESULTS Fifty (40%) patients showed myocardial DE, representing 12±7% of LV mass. During a median follow-up of 14.2months, 16 (32%) patients with DE experienced a composite event versus only 6 (8%) patients without DE (Kaplan-Meier survival curve, p=0.001). After correction for age, CMR-derived LV and right ventricular volumes, echocardiographic measurements of LV diastolic function and Doppler-estimated systolic pulmonary artery pressure, the presence of DE remained a strong and independent predictor of cardiac death or HF hospitalization (hazard ratio: 5.32, 95% confidence intervals 1.60 to 17.63, p=0.006). CONCLUSIONS In NICM patients with no or mild HF symptoms, the presence of myocardial DE is a strong predictor of worse clinical outcome even after correction for other established prognostic determinants. Contrast-enhanced CMR may be useful in prognostic stratification from the early stages of NICM.

Valvular heart disease: what does cardiovascular MRI add?

Although ischemic heart disease remains the leading cause of cardiac-related morbidity and mortality in the industrialized countries, a growing number of mainly elderly patients will experience a problem of valvular heart disease (VHD), often requiring surgical intervention at some stage. Doppler-echocardiography is the most popular imaging modality used in the evaluation of this disease entity. It encompasses, however, some non-negligible constraints which may hamper the quality and thus the interpretation of the exam. Cardiac catheterization has been considered for a long time the reference technique in this field, however, this technique is invasive and considered far from optimal. Cardiovascular magnetic resonance imaging (MRI) is already considered an established diagnostic method for studying ventricular dimensions, function and mass. With improvement of MRI soft- and hardware, the assessment of cardiac valve function has also turned out to be fast, accurate and reproducible. This review focuses on the usefulness of MRI in the diagnosis and management of VHD, pointing out its added value in comparison with more conventional diagnostic means.

Determination of regional ejection fraction in patients with myocardial infarction by using merged late gadolinium enhancement and cine MR: feasibility study.

PURPOSE To quantify regional ejection fraction (EF) in patients with myocardial infarction (MI) by using merged late gadolinium enhancement (LGE) and cine magnetic resonance (MR) imaging, and compare this method with the standardized 17-segment American Heart Association approach. MATERIALS AND METHODS After institutional review board approval and informed consent, 15 MI patients (14 men, one woman; mean age, 63 years +/- 10 [standard deviation]) were studied at 1 week and at 4 months after MI. Short-axis LGE MR information was used to quantify infarct size, and to divide the left ventricle (LV) on short-axis cine MR images in infarct, periinfarct, and remote regions by using a fixed-center method, yielding information on regional volumes, regional EFs, systolic wall thickening (SWT), and systolic wall motion (SWM). This approach was compared with a floating-center approach and the 17-segment approach. RESULTS Mean infarct size (normalized to LV mass) was 25% +/- 14 at 1 week and 16% +/- 8 at 4 months (P < .001). At 4 months, LV EF significantly improved (mean, 47.9% +/- 5.9 vs 50.9% +/- 6.6, P = .031), matching an improvement of regional EF (mean, 17.1% +/- 11.5 vs 24.6% +/- 13.1, P = .005) and SWM (mean, 3.2 mm +/- 1.7 vs 3.9 mm +/- 2.1, P = .027) in the infarcted myocardium. No significant changes in regional EF, SWT, or SWM occurred in the remote myocardium. Regional EF estimates correlated well with SWT and SWM (both r = 0.92, P < .001). The floating-center method invariably underestimated regional EF (mean, -20.8% +/- 7.6; 95% confidence interval: -23.7%, -17.9%), especially with increasing infarct size. By using the 17-segment approach, no functional improvement was shown in the infarcted myocardium. CONCLUSION Assessment of regional ventricular performance (regional EF) in well-defined areas (eg, infarcted and remote myocardium) is feasible by using merged LGE and cine MR imaging.