Prevalence and prognostic impact of nonischemic late gadolinium enhancement in stress cardiac magnetic resonance

Absence of long-term incremental prognostic value of inducible wall motion abnormalities on dipyridamole stress CMR in patients with suspected or known coronary artery disease

OBJECTIVES

This single-center retrospective study evaluated the long-term (~5 years) prognostic value of dipyridamole stress cardiac magnetic resonance (CMR) in patients with known or suspected coronary artery disease (CAD), assessing the impact of both key phases of the ischemic cascade (perfusion and wall motion).

MATERIAL AND METHODS

We considered 322 consecutive patients who underwent dipyridamole stress CMR. Abnormal wall motion at rest and after dipyridamole, perfusion at stress and at rest, and late gadolinium enhancement (LGE) were analyzed. End-points were non-fatal myocardial infarction, unplanned late revascularization (60 days after CMR), and cardiac death.

RESULTS

Forty-four patients were excluded because they underwent early revascularization (within 60 days after stress CMR), leading to a final population of 278 patients (73 females, 62.42 ± 10.50 years). A positive stress CMR was found in 78 (28.1%) patients; 50 patients had a reversible stress perfusion defect in at least one myocardial segment and 28 had a reversible stress perfusion defect plus worsening of stress wall motion in comparison with the rest. During a mean follow-up time of 59.34 ± 31.72 months, 37 (13.3%) cardiac events were recorded: 10 cardiac deaths, one non-fatal myocardial infarction, and 26 late revascularization after unstable angina or myocardial infarction. According to the Cox regression analysis, age, diabetes mellitus, previous revascularization, left ventricular ejection fraction (LVEF), reversible perfusion and perfusion + motion defect, and LGE were significant univariate prognosticators. The presence of associated wall motion abnormality (WMA) did not provide additional prognostic stratification in comparison to the only perfusion defect. In the multivariate Cox regression, the independent predictive factors were diabetes (hazard-ratio-HR = 5.64, p < 0.0001), reversible perfusion defect and reversible perfusion + motion defect vs normal stress CMR (HR = 6.43, p < 0.0001, and HR = 4.57, p = 0.004; respectively), and LVEF (HR = 0.96, p = 0.010).

CONCLUSION

A positive dipyridamole stress CMR predicted a higher long-term risk of cardiovascular events, but the presence of inducible WMA did not show any additional prognostic value over the reversible perfusion defect.

KEY POINTS

Question The long-term incremental prognostic value of inducible wall motion abnormalities by stress cardiac MR in patients with known or suspected CAD requires investigation. Findings The presence of inducible wall motion abnormalities did not offer additional prognostic value in comparison to the only reversible perfusion defect. Clinical relevance Independent from the presence of wall motion abnormalities, more aggressive management may be appropriate in patients with reversible perfusion defects to reduce the long-term risk of cardiovascular events.

The additive prognostic value of end-systolic pressure-volume relation by stress CMR in patients with known or suspected coronary artery disease

PURPOSE

The difference between rest and peak stress end-systolic pressure-volume relation (ΔESPVR) is an afterload-independent index of left ventricular (LV) contractility. We assessed the independent prognostic value of ΔESPVR index by dipyridamole stress-cardiovascular magnetic resonance (CMR) in patients with known/suspected coronary artery disease (CAD).

METHODS

We considered 196 consecutive patients (62.74 ± 10.66 years, 49 females). Wall motion and perfusion abnormalities at rest and peak stress were analysed. Replacement myocardial fibrosis was detected by late gadolinium enhancement (LGE) technique. The ESPVR was evaluated at rest and peak stress from raw measurement of systolic arterial pressure and end-systolic volume by biplane Simpson's method.

RESULTS

A reduced ΔESPVR index (≤ 0.02 mmHg/mL/m2) was found in 88 (44.9%) patients and it was associated with a lower LV ejection fraction (EF) and with a higher frequency of abnormal stress CMR and myocardial fibrosis. During a mean follow-up of 53.17 ± 28.21 months, 50 (25.5%) cardiac events were recorded: 5 cardiac deaths, 17 revascularizations, one myocardial infarction, 23 hospitalisations for heart failure or unstable angina, and 4 ventricular arrhythmias. According to Cox regression analysis, diabetes, family history, LVEF, abnormal stress CMR, myocardial fibrosis, and reduced ΔESPVR were significant univariate prognosticators. In the multivariate analysis the independent predictors were ΔESPVR index ≤ 0.02 mmHg/mL/m2 (hazard ratio-HR = 2.58, P = 0.007), myocardial fibrosis (HR = 2.13, P = 0.036), and diabetes (HR = 2.33, P = 0.012).

CONCLUSION

ΔESPVR index by stress-CMR was independently associated with cardiac outcomes in patients with known/suspected CAD, in addition to replacement myocardial fibrosis and diabetes. Thus, the assessment of ΔESPVR index may be included into the standard stress-CMR exam to further stratify the patients.

Determinants of worse prognosis in patients with cardiac resynchronization therapy defibrillators. Are ventricular arrhythmias an adjunctive risk factor?

AIMS

Cardiac resynchronization therapy (CRT) is indicated in patients with systolic heart failure (HF), severe left ventricle (LV) dysfunction and interventricular dyssynchrony.In prospective observational research, we aimed to evaluate whether CRT-induced LV reverse remodelling and occurrence of ventricular arrhythmias (VT/VF) independently contribute to prognosis in patients with CRT defibrillators (CRT-D).

METHODS

In 95 Italian cardiological centres, after a screening period of 6 months, patients were categorized according to VT/VF occurrence and CRT response, defined as LV end-systolic volume relative reduction >15% or LV ejection fraction absolute increase >5%. The main endpoint was death or HF hospitalizations.

RESULTS

Among 1308 CRT-D patients (80% male, mean age 66 years), at 6 months, follow-up 71% were identified as CRT responders and 12% experienced appropriate VT/VF detections. The main endpoint was significantly and independently associated with previous myocardial infarction, New York Heart Association Class, VT/VF occurrence and with CRT response. CRT nonresponder patients who suffered VT/VF in the screening period had a risk of death or HF hospitalizations [HR = 7.82, 95% confidence interval (CI) = 3.95-15.48] significantly (P < 0.001) higher than CRT responders without VT/VF occurrence. This risk is mitigated without VT/VF occurrence (HR = 3.47, 95% CI = 2.03-5.91, P < 0.001) or in case of CRT response (HR = 3.11, 95% CI = 1.44-6.72, P = 0.004).

CONCLUSION

Our data show that both CRT response and occurrence of VT/VF independently contribute to the risk of death or HF-related hospitalizations in CRT-D patients. Early VT/VF occurrence may be identified as a marker of disease severity than can be mitigated by CRT response both in terms of all-cause mortality and long-term VT/VF onset.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT00147290 and NCT00617175.