Diagnostic and Clinical Impact of Cardiac Magnetic Resonance Imaging at a Tertiary Care Center: A Comprehensive Analysis

ABSTRACT IMAGE

INTRODUCTION

Despite considerable progress in diagnosis and treatment, cardiovascular disease (CVD) continues to be the leading cause of morbidity and mortality worldwide, accounting for nearly one-third of all annual deaths.^[1-3] Early and precise diagnosis is crucial for improving outcomes in patients with CVD. Cardiovascular imaging plays a pivotal role in guiding diagnostic decisions and monitoring treatment follow-up in CVD.^[1]

Cardiovascular magnetic resonance (CMR) has become a key imaging modality for the diagnosis and management of CVDs, offering exceptional insights into cardiac structure, function, and tissue characterization.^[4] It is utilized for various clinical indications, mostly in cases of inflammatory and ischemic heart diseases as well as different cardiomyopathies. By integrating multiple techniques, CMR provides comprehensive information on cardiovascular anatomy and function, including assessments of cardiac size, contractility, edema, fibrosis, and perfusion.^[5] The commonly used CMR sequences and their clinical utility are summarized in Box 1 [Supplementary File].^[6] CMR has specific advantages and disadvantages when compared to other modalities, which are summarized in Box 2 [Supplementary File].^[6]

Although the diagnostic importance of CMR is well recognized, its availability varies significantly, not only between different countries but also across regions within the same country. This disparity is often linked to limited access to scanners equipped for cardiac imaging, insufficient expertise to perform and interpret CMR, and differences in health insurance systems regarding reimbursement policies.^[5]

Operational challenges – including long waiting times, a shortage of specialized scanners, and limited numbers of high-volume centers – contribute to its underutilization in many healthcare settings.^[7-9] Variations in training and operator expertise, coupled with the complexities of coordinating multidisciplinary teams of cardiologists and radiologists, further impact the timely and high-quality delivery of CMR services.^[10] Although the diagnostic and prognostic utility of CMR is well supported by Western literature, similar data from Indian healthcare systems are limited. This is important because many Indian tertiary centers, including ours, operate under significant constraints, restricted CMR scanner access, high inpatient volumes, limited trained staff, and procedural delays linked to contrast-safety evaluations. Given these challenges, we carried out this audit to provide real-world data on the diagnostic yield, image quality, and clinical impact of CMR in a tertiary care center.

MATERIALS AND METHODS

Image quality

The quality of steady-state free-precession cines and delayed enhancement images was evaluated by a Level 3 EACVI-accredited operator with over 5 years of experience in CMR. Cine images were categorized as good, adequate, or poor. Good indicated high-quality short-axis and long-axis images with no significant artifacts. Adequate images referred to images with minimal artifacts that still allowed accurate measurement of cardiac volumes with high confidence. Poor denoted images of insufficient quality to reliably measure cardiac volumes or determine ejection fraction.

Similarly, the delayed enhancement images were also classified as good, adequate, or poor. As with the cine images, good represented studies with high-quality long- and short-axis views free of significant artifacts. Adequately described images with minor artifacts that still permitted a confident clinical diagnosis. Poor indicated non-diagnostic images. No patients were excluded from the study based solely on image quality; even in cases where individual sequences were non-diagnostic, the CMR scan and clinical decision outcomes were retained in the dataset [Figure 1].

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Figure 1:

Study flow diagram (as per strobe guidelines). (CMR: Cardiac magnetic resonance Imaging, LGE: Late gadolinium enhancement.)

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RESULTS

The demographic and baseline characteristics of the study population are summarized in Table 1. A total of 210 inpatients were included, of whom 128 (60.95%) were male and 82 (39.05%) were female. Most of the patients were older adults, with the highest proportion belonging to the 61–80 years of age group: 88 (41.90%), followed by 71 (33.81%) in the 41–60 years of age group. Cardiovascular risk factors were common, with hypertension in 69 (32.86%), diabetes in 41 (19.52%), dyslipidemia in 24 (11.43%), and smoking/tobacco use in 36 (17.14%) patients. A family history of coronary artery disease (CAD) was reported in 12 (5.71%) patients.

With regard to pre-existing cardiac conditions, 67 (31.9%) had known CAD or prior MI, 29 (13.81%) had previously documented heart failure, 18 (8.57%) had known cardiomyopathy, 8 (3.81%) had valvular heart disease, and 14 (6.67%) had a history of atrial fibrillation or arrhythmia. Notably, a substantial proportion – 74 patients (35.24%) – had no previously known cardiac disease, reflecting the use of CMR for initial diagnostic clarification in patients presenting with new or unexplained cardiac symptoms.

Viability assessment was the prime indication for CMR, accounting for 118 (56.19%) of scans. Cardiomyopathy constituted 46 (21.90%) of referrals and included the assessment of the left ventricular systolic dysfunction (LVSD) and the characterization of specific cardiomyopathic processes such as hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM), cardiac amyloidosis, and arrhythmogenic cardiomyopathy. Myocarditis accounted for 19 (9.05%) of referrals. Post-cardiac arrest evaluation and suspected CAD each accounted for 8 (3.81%) of scans. The remaining 11 (5.24%) cases were for other indications, including pericardial disease, cardiac masses, and infiltrative conditions [Figure 2]. The most common diagnosis following inpatient CMR scanning was ischemic cardiomyopathy/CAD, identified in 92 (43.80%) cases. Cardiomyopathy was the second most frequent diagnosis, with 65 (31%) patients classified as having non-ICM (NICM), including HCM. Intracardiac thrombus (ventricular or atrial) was detected in 25 (11.90%) cases. Myocarditis accounted for 15 (7.14%) of cases, consistent with the established role of CMR in identifying myocardial inflammation. Pericardial diseases were noted in 7 (3.33%) cases, while cardiac tumors were detected in 6 (2.86%) cases. All tumors were diagnosed as atrial myxomas on CMR, of which five were located in the left atrium and one in the right atrium [Table 2].

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Figure 2:

Primary indications for cardiovascular magnetic resonance scan. (CAD: Coronart artery disease.)

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The overall image quality of CMR scans was predominantly good, with 145 (69.05%) cine images and 128 (60.95%) late gadolinium enhancement (LGE) images rated as good quality. Adequate quality was achieved in 53 (25.24%) cine images and 61 (29.05%) LGE images. Poor-quality images were relatively uncommon, comprising 8 (3.81%) cine and 12 (5.71%) LGE scans. In a small subset of cases, images were not obtained, including 4 (1.90%) cine and 9 (4.29%) LGE sequences [Figure 3].

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Figure 3:

Image quality of cardiovascular magnetic resonance scan. (CMR: Cardiac Magnetic resonance imaging, LGE: Late gadolinium enhancement).

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Safety: No serious contrast reactions or scan-related complications occurred.

Table 3 describes the impact of CMR findings on inpatient management. CMR had a significant influence on clinical decision-making in this study. CMR findings prompted major medication changes in 94 (44.76%) patients, including uptitration or initiation of new medications in 63 (30%) and dose adjustments in 31 (14.76%). Revascularization decisions were made in 88 (41.9%) patients, with PCI performed in 60 (28.57%) and coronary artery bypass grafting (CABG) in 28 (13.33%). Device therapy was undertaken in 34 (16.19%) patients, including ICD implantation in 25 (11.90%) and cardiac resynchronization therapy (CRT) implantation in 9 (4.29%). Surgical or structural interventions were performed in 18 (8.57%) patients, including myectomy in 7 (3.33%), valve surgery in 6 (2.86%), and tumor resection in 5 (2.38%). Anticoagulation therapy was initiated in 25 (11.90%) patients, and immunosuppression or anti-inflammatory therapy was initiated in 16 (7.62%). In 1 (0.48%) patient, immunosuppressive therapy was withheld based on CMR findings.

CMR findings also led to the deferral of procedures, including CABG in 4 (1.9%), PCI in 13 (6.19%), ICD implantation in 9 (4.29%) patients, and CRT implantation in 2 (0.95%) patients. In addition, tumor resection could not be performed in 1 (0.48%) patient due to refusal to consent.

Among the 118 patients referred for viability assessment, 92 (78%) patients were diagnosed with CAD on CMR and comprised the analysis cohort. Following CMR interpretation, PCI was initially deferred in 13 (14.1%) patients due to unfavorable coronary anatomy or inadequate viability, while CABG was deferred in 4 (4.3%) patients. Final revascularization decisions were mutually exclusive: 60 (65.2%) patients underwent PCI, and 28 (30.4%) patients underwent CABG. Revascularization was ultimately deferred in 4 (4.3%) patients based on persistently poor viability or prohibitive surgical risk [Table 4]. These data demonstrate that CMR-directed evaluation resulted in definitive revascularization in 96% of CAD-positive patients, with only a small proportion remaining unsuitable for intervention.

DISCUSSION

This clinical audit was conducted at our tertiary care center to underscore critical insights into the current state of clinical utility of CMR. The demographic data revealed that the majority of patients belonged to the 41–80 years of age group (~76%), with a male predominance. Patient characteristics revealed hypertension as the most common cardiac risk factor and a contributor to cardiovascular morbidity. A substantial burden of CAD was observed. Notably, 74 (35.24%) patients had no known cardiac comorbidities, underscoring the utility of CMR as a valuable diagnostic tool in patients with new or unexplained cardiac symptoms.

Our audit showed that viability assessment was the predominant indication in ischemic heart disease, guiding revascularization decisions. Myocarditis was observed in 9.05% of cases, which is consistent with the established role of CMR in diagnosing inflammatory heart disease. Indications of post-cardiac arrest evaluation and suspected CAD were detected in 3.81% of CMR referrals, reflecting the value of CMR in identifying the underlying causes and its role in evaluating ischemic heart disease, particularly when other imaging modalities were inconclusive. In concurrence with our audit, Monti et al., reported that the proportion of participants expressing complete or partial agreement in considering CMR in established clinical indication was very high when assessing cardiomyopathies (100%), myocarditis (99%), cardiac masses/tumors (98%), congenital heart diseases (95%), or myocardial infarction with non-obstructive coronary arteries (MINOCA) (93%), but lower when indication is represented by valvular heart diseases (68%), diseases of the thoracic aorta (67%), and acute coronary syndromes other than MINOCA (53%).^[4]

A high burden of ischemic heart disease among hospitalized patients undergoing CMR was noted in our study. 31% of our study cohort was diagnosed with cardiomyopathy based on CMR, highlighting the role of CMR in evaluating structural and functional myocardial abnormalities, including conditions such as hypertrophic and dilated cardiomyopathy. Furthermore, CMR plays a pivotal role in differentiating nonischemic causes of heart failure and guiding the management of patients. CMR contributed to the detection of intracardiac thrombus (atrial/ventricular) as part of a comprehensive cardiac evaluation. These findings were interpreted alongside echocardiography and clinical assessment before anticoagulation decisions were made. In addition, CMR’s strength in assessing pericardial anatomy, pathology, and cardiac tumors was established through our study. Overall, survey findings with regard to the diagnosis of the study cohort emphasize the broad diagnostic utility of CMR across a range of cardiac conditions in the inpatient setting.

In our survey, 94% of cine images were of diagnostic quality. Although this is slightly lower than the 98% reported in the EuroCMR registry,^[11] the difference is not unexpected. This can be attributed to the fact that inpatients are generally more clinically unstable and decompensated than outpatients, making it harder to acquire high-quality diagnostic images due to challenges such as breath-holding difficulties and arrhythmias.^[12] Abraham et al. reported diagnostic image quality in 99.9% of cases, which is higher than what we observed in our inpatient group, as would be expected in a more stable patient population.^[13]

Bruder et al. presented the first dataset assessing clinical routine image quality of CMR in a European setting, and demonstrated that CMR successfully addresses relevant clinical questions in over 98% of cases. This finding suggests that current CMR practices consistently produce a high proportion of diagnostically valuable studies, likely due to superior image quality. Notably, this was validated in a multinational, multi-ethnic, consecutive clinical routine setting that included a broad patient population – such as individuals with dyspnea at rest, atrial fibrillation, obesity (BMI range 23.7–29.3 kg/m²), and other common cardiac conditions known to affect image quality.^[11] Overall, the average image quality achieved with CMR in routine clinical use surpasses that of other noninvasive imaging modalities, including echocardiography,^[14] cardiac CT,^[15,16] and SPECT.^[17] In addition, since CMR does not involve ionizing radiation, it can be safely repeated as needed for ongoing follow-up assessments.^[11]

In our clinical audit, CMR findings led to major medication changes in 44.8% of patients and revascularization decisions in 41.9%. Medication dose adjustments reflected overall clinical decision-making following diagnostic clarification by CMR, rather than direct CMR-guided titration. CMR refined viability assessment and myocardial tissue characterization, which assisted clinical decision-making in selected patients. However, coronary angiography remained the principal modality guiding revascularization decisions such as PCI and CABG. Furthermore, CMR findings led patients to undergo [Figure 4] device therapies (16.19%), surgical or structural interventions (8.57%). In addition, anticoagulation and immunosuppression/anti-inflammatory therapies were initiated in 11.90% and 7.62% of patients based on CMR investigation outcomes. In addition, in one patient (0.48%), immunosuppression/anti-inflammatory therapy was withheld/stopped based on CMR investigations. Furthermore, CMR findings deferred decisions on CABG, PTCA, ICD implantation, and CRT implantation in 1.9%, 6.19%, 4.29%, and 0.95% of patients, respectively. Our findings regarding the impact of CMR on inpatient management were consistent with the EuroCMR registry, where CMR influenced patient management in 62% of cases.^[11]

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Figure 4:

Depiction of national online survey findings of SIC CMR working group.

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In this cohort, CMR-based viability assessment provided a framework for guiding revascularization strategy, with 96% of CAD-positive patients ultimately undergoing either PCI or CABG. The very small proportion of patients in whom revascularization was finally deferred (4.3%) highlights the discriminative strength of CMR in differentiating recoverable myocardium from irreversible scar. These findings align with foundational work demonstrating that the extent of late gadolinium enhancement strongly predicts segmental functional recovery after revascularization, positioning CMR as a reliable modality for viability assessment compared with nuclear or dobutamine-based techniques.^[18] Importantly, the initial deferral of PCI in a subset of patients – several of whom were subsequently reassigned to CABG – underscores the incremental value of CMR in complementing angiographic findings, particularly in the context of multivessel or anatomically complex disease. By integrating myocardial substrate, ischemic burden, and anatomical feasibility, CMR supported more individualized and evidence-aligned revascularization decisions.

These observations also need to be considered within the broader evidence base evaluating the role of viability in ICM. Early analyses from the STICH viability sub-study reported a limited association between viability and survival benefit, though the extended STICHES follow-up demonstrated a durable prognostic advantage of surgical revascularization, especially in patients with retained myocardial viability.^[19,20] More recently, the REVIVED-BCIS2 trial showed that PCI did not uniformly improve outcomes in severe ischemic left ventricular dysfunction, further emphasizing the necessity of precise substrate assessment when selecting candidates for revascularization.^[21] In this context, CMR – owing to its detailed characterization of scar burden, transmurality, and border-zone tissue – offers a mechanistic explanation for differential treatment benefit. Our findings, demonstrating clear stratification between patients directed toward PCI, CABG, or conservative management, reinforce the concept that CMR-guided viability assessment may enhance patient selection and optimize the therapeutic value of revascularization.

A national online survey conducted by the SIC CMR Working Group in Italy aimed to evaluate the awareness of CMR’s clinical value and gather information on its local use, operational challenges, and reporting effectiveness. The goal was to identify the main barriers to its efficient implementation across the country. The survey found that, although CMR is widely recognised for its clinical benefits, it remains underutilized, primarily due to operational issues such as long waiting times and insufficient specialized expertise. In addition, concerns about the quality of reports were frequently noted, leading to a significant number of second-opinion requests [Figure 4, Supplementary File].^[4]

Moreover, Betemariam et al. conducted a systematic review of literature spanning from 2003 to 2023, which identified several key barriers to the widespread use of CMR. These included the limited availability of CMR scanners, leading to prolonged waiting times, high operational costs, insufficient training opportunities, and the absence of a standardized curriculum. The review also highlighted notable geographical disparities in CMR utilization. Globally, most CMR training programs are based within radiology departments. The observed geographic variations and heterogeneity in training programs reflect the impact of systemic factors such as healthcare infrastructure, reimbursement policies, and the lack of standardized training frameworks.^[22]

In the Indian context, the findings of this audit underscore the growing importance of integrating CMR into tertiary inpatient care. Despite limited availability and higher procedural costs compared to echocardiography or CT, CMR offers comprehensive diagnostic information in a single sitting, often preventing unnecessary angiography, device implantation, or surgical exploration. Such precision not only optimizes treatment pathways but also conserves healthcare resources in a cost-sensitive system. Broader access to well-trained CMR teams and streamlined referral protocols could improve diagnostic confidence across diverse cardiac presentations, particularly in centers managing complex heart failure or unexplained cardiomyopathy. Expanding domestic expertise and awareness among clinicians remains essential to ensure CMR’s transition from a tertiary privilege to a routine diagnostic pillar in Indian cardiology practice. Given the underrepresentation of women in CMR data, future analyses should explore gender-specific patterns and diagnostic yields in Indian populations.

CONCLUSION

To the best of our knowledge, this is one of the first Indian single-center audits of inpatient CMR examining management change as an endpoint. Viability assessment, cardiomyopathy, and myocarditis were identified as the three most frequent indications for CMR. ICM/CAD, NICM and thrombus were identified as the top three diagnoses accomplished through CMR scans. The image quality was diagnostic for both cine and LGE images. Furthermore, CMR had a promising impact on the management of inpatients at our tertiary care center, corroborating the EuroCMR registry outcomes. Our findings demonstrate that implementing high-quality CMR within tertiary centers in developing regions can substantially enhance diagnostic precision and optimise patient management. Expanding CMR infrastructure and training programs could bridge existing global imaging disparities. However, future multicenter prospective Indian registries will be essential to validate these findings and address training and infrastructure barriers.