Myocardial scar identified by magnetic resonance imaging can predict left ventricular functional improvement after coronary artery bypass grafting

Assessment of Myocardial Viability in Ischemic Cardiomyopathy With Reduced Left Ventricular Function Undergoing Coronary Artery Bypass Grafting

BACKGROUND

We aim to provide a comprehensive review of the current state of knowledge of myocardial viability assessment in patients undergoing coronary artery bypass grafting (CABG), with a focus on the clinical markers of viability for each imaging modality. We also compare mortality between patients with viable myocardium and those without viability who undergo CABG.

METHODS

A systematic database search with meta-analysis was conducted of comparative original articles (both observations and randomized controlled studies) of patients undergoing CABG with either viable or nonviable myocardium, in EMBASE, MEDLINE, Cochrane database, and Google Scholar, from inception to 2022. Imaging modalities included were dobutamine stress echocardiography (DSE), cardiac magnetic resonance (CMR), single-photon emission computed tomography (SPECT), and positron emission tomography (PET).

RESULTS

A total of 17 studies incorporating a total of 2317 patients were included. Across all imaging modalities, the relative risk of death post-CABG was reduced in patients with versus without viability (random-effects model: odds ratio: 0.42; 95% confidence interval: 0.29-0.61; p < 0.001). Imaging for myocardial viability has significant clinical implications as it can affect the accuracy of the diagnosis, guide treatment decisions, and predict patient outcomes. Generally, based on local availability and expertise, either SPECT or DSE should be considered as the first step in evaluating viability, while PET or CMR would provide further evaluation of transmurality, perfusion metabolism, and extent of scar tissue.

CONCLUSION

The assessment of myocardial viability is an essential component of preoperative evaluation in patients with ischemic heart disease undergoing surgical revascularization. Careful patient selection and individualized assessment of viability remain paramount.

Prediction of left ventricular ejection fraction improvement in patients with ischemic cardiomyopathy after coronary artery bypass grafting based on cardiac magnetic resonance

Background

To investigate the risk factors of left ventricular ejection fraction (LVEF) improvement in patients with ischemic cardiomyopathy (ICM) after coronary artery bypass grafting (CABG), and to construct a model that predicts LVEF improvement.

Methods

A retrospective analysis was performed on 106 ICM patients who received CABG and underwent cardiac magnetic resonance (CMR) at Beijing Anzhen Hospital, Capital Medical University from January 2017 to June 2022. Patients were divided into two groups with improved LVEF and no improved LVEF based on the results of postoperative 6-month transthoracic echocardiography. To analyze the risk factors affecting the LVEF non-improvement after CABG and establish a prediction model.

Results

There was LVEF non-improvement in 30.2% (32/106) of patients. Multivariate analysis showed that the number of transmural scar segments and left ventricular end-systolic volume index (LVESVI) were independent risk factors in LVEF non-improvement after CABG [odds ratio (OR) =2.398, 95% confidence interval (CI): 1.607-3.579, P<0.001; OR =1.036, 95% CI: 1.009-1.063, P=0.008]. The model is built and internally verified. ROC showed that the area under the curve (AUC) was 0.866 (95% CI: 0.792-0.940), calibration curve showed that the probability predicted by the model matched well with the clinical results, and decision curve analysis (DCA) showed that the model had good clinical applicability. During the mean follow-up time of 1.5 years, the incidence of major adverse cardiovascular and cerebrovascular events (MACCE) in the LVEF non-improvement group was higher (5.4% vs. 25.0%, P=0.009), and the NYHA grading was higher (P=0.016), when compared to the LVEF improvement group.

Conclusions

The prediction model based on the number of transmural scar segments and LVESVI has good diagnostic efficacy. Our findings help to identify patients with improved LVEF and thus guide the selection of clinical treatment strategies.

Myocardial infarct size for predicting improvements in cardiac function in patients with ischemic cardiomyopathy following coronary artery bypass grafting

Background

This study used late gadolinium enhancement-cardiac magnetic resonance (LGE-CMR) to assess myocardial infarct size, with the data being employed to predict whether patients with ischemic cardiomyopathy (ICM) would experience improvements in left ventricular function at 6 months following coronary artery bypass grafting (CABG).

Methods

The data of patients with ICM with left ventricular ejection fraction (LVEF) ≤40% who underwent CABG were retrospectively analyzed. All patients underwent preoperative LGE-CMR imaging. Echocardiography results from 6 months post-CABG were used to assess improvements in LVEF, with improvement being defined as ΔLVEF ≥5%. The value of myocardial infarction segments and infarct size as predictors of improved cardiac function following CABG was analyzed.

Results

Of the included patients, 66.7% (52/78) exhibited improved cardiac function at 6 months post-CABG. LGE-CMR imaging data revealed that compared to improved group, the improved group had significantly more myocardial infarct segments [improved group: median 1.0, interquartile range (IQR) 0-3; nonimproved group: median 4.0, IQR 3.0-6.0; P<0.001] and significantly greater myocardial infarct size (improved group: 22.4%±8.2%; nonimproved group: 34.7%±5.9%; P<0.001). The area under the receive operating characteristic curve values for myocardial infarct size in predicting cardiac function improvement were significantly higher than those of myocardial infarct segments (0.88 vs. 0.81; P=0.041). The respective sensitivity and specificity values for using a myocardial infarct size cutoff of 26.4% in differentiating between these 2 patient groups were 92.3% and 71.2%, respectively. According to logistic regression analysis, myocardial infarct size was an independent predictor of nonimprovement in cardiac function [odds ratio (OR) =1.244; 95% confidence interval (CI): 1.114-1.389; P<0.001]. A median 1.6-year follow-up interval (range, 0.5-4.1 years) revealed that the incidences of major adverse cerebrovascular events and cardiovascular events were significantly higher in the nonimproved group (5.8% vs. 26.9%; P<0.001), with these individuals having a higher New York Heart Association grading than patients with improved cardiac function (P=0.019).

Conclusions

Myocardial infarct size can be measured to reliably predict improvements in cardiac function in patients with ICM following CABG. These results can guide clinicians in their efforts to identify those patients most likely to achieve positive outcomes following CABG.

Long-term outcomes after coronary artery bypass graft with or without surgical ventricular reconstruction in patients with severe left ventricular dysfunction

Background

Patients with chronic myocardial infarction (MI) and severe left ventricular (LV) dysfunction have poor clinical outcomes. This study aimed to determine whether coronary artery bypass graft (CABG) with surgical ventricular reconstruction (SVR) leads to further improvement in long-term patient outcomes compared with isolated CABG (I-CABG).

Methods

From April 2010 to June 2013, 140 consecutive patients with chronic MI and severe LV dysfunction who received contrast-enhanced cardiovascular magnetic resonance imaging (CE-CMR) within 1 month before surgery were enrolled in this study. The cardiovascular events (CVEs) and long-term survival of patients who underwent CABG and SVR were compared with those who met the criteria for SVR but received I-CABG.

Results

A total of 140 patients were included in the final analysis, including 70 patients who underwent CABG and SVR and 70 patients who underwent I-CABG. No differences were observed in the baseline characteristics, LV function, and late gadolinium enhancement (LGE) between the two groups. CABG+SVR patients experienced a longer cardiopulmonary bypass (CPB) time (116.0±35.0 vs. 100.2±23.8 minutes, P=0.002) and ventilation time [median (interquartile range): 22.0 (17.0, 37.0) vs. 20.0 (15.0, 24.0) hours, P=0.019] than I-CABG patients. During a mean follow-up of 123.1±12.7 months (range, 102-140 months), the CABG+SVR group had fewer rehospitalizations for congestive heart failure (CHF) (4.3% vs. 19.1%, P=0.007), but no statistical difference in the mortality rate was observed (2.9% vs. 4.4%, P=0.987). The cumulative CVE-free survival rate was significantly higher in CABG+SVR patients (87.0% vs. 67.6%, P=0.007).

Conclusions

Our findings indicated that patients with chronic MI and severe LV dysfunction experienced similar perioperative outcomes after CABG+SVR or I-CABG. However, the CABG+SVR group resulted in fewer rehospitalizations for CHF and a higher cumulative CVE-free survival rate.

Retrospective, observational analysis of cardiac function associated with global preoperative myocardial scar in patients with ischemic cardiomyopathy after coronary artery bypass grafting

BACKGROUND

Drawing on accumulated patient data from a hospital database, the goal of this retrospective study was to analyze cardiac function associated with global preoperative myocardial scarring assessed by cardiac magnetic resonance with late gadolinium enhancement (CMR-LGE) in patients with ischemic cardiomyopathy (ICM) after coronary artery bypass grafting (CABG).

METHODS

A total of 57 patients diagnosed with ICM who underwent isolated CABG at Beijing Anzhen Hospital between September 2017 and September 2019 were enrolled in this retrospective study. All these patients underwent a preoperative CMR-LGE examination. Based on postoperative echocardiography results at 6 months, cases were divided into the following 2 groups: improved cardiac function [a difference of left ventricular ejection fraction (LVEF) greater than or equal to 5%] and unimproved cardiac function. The factors contributing to these patients' unimproved cardiac function were investigated.

RESULTS

At 6 months after surgery, 64.9% (37/57) of cases had improved cardiac function, and 35.1% (20/57) had no improvement. There was no statistical difference between the 2 groups in the Synergy Between Percutaneous Coronary Intervention With Taxus and Cardiac Surgery (SYNTAX) score (41.7±7.6 vs. 42.8±8.3; P=0.603), but compared to the improved group, preoperative myocardial scarring was significantly enlarged in the unimproved group (41.9%±6.4% vs. 27.8%±8.5%; P<0.001). In regression analysis, only preoperative myocardial scarring [odds ratio (OR) =1.44; 95% confidence interval (CI): 1.13-1.83; P=0.003] was associated with no change in cardiac function evaluated by echocardiography after CABG. The median follow-up of 1.6 years (range, 0.6-4.1 years) found that the unimproved group had a higher incidence of major adverse cardiovascular and cerebrovascular events (MACCEs) (8.1% vs. 25.0%; P=0.044), and that the New York Heart Association (NYHA) classification of the unimproved group was higher than that of the improved group (P=0.018).

CONCLUSIONS

In ICM patients, a greater amount of preoperative myocardial scarring is associated with unimproved cardiac function after CABG. The measurement of preoperative myocardial scarring may aid clinicians in identifying patients who would benefit from CABG.

Myocardial viability assessment and utility in contemporary management of ischemic cardiomyopathy

Background

In clinical practice, we encounter ischemic cardiomyopathy (ICM) with underlying viable, dysfunctional myocardium on a regular basis. Evidence from the Surgical Treatment for Ischemic Heart failure (STICH) and its Extension Study is supportive of improved outcomes with coronary revascularization, irrespective of myocardial viable status. However, Dobutamine stress echocardiography (DSE) and single‐photon emission computed tomography (SPECT), used in STICH to assess myocardial viability may fail to distinguish hibernating myocardium from scar due to suboptimal image resolution and poor tissue characterization.

Hypothesis

Cardiac magnetic resonance (CMR) and positron emission tomography (PET) can precisely quantify myocardial scar and identify metabolically active, viable myocardium respectively. Unlike DSE and SPECT, CMR and PET allow examining myocardial status as a contiguous spectrum from viable to partially viable myocardium with varying degrees of subendocardial scar and nonviable myocardium with predominantly transmural scar, the therapeutic and prognostic determinants of ICM.

Methods

Under the guidance of CMR and PET imaging, myocardium can be distinguished viable from partially viable with subendocardial scar and predominantly transmural scar. In ICM, optimal medical therapy and coronary revascularization of viable/partially viable myocardium but not transmural scar may improve outcomes in patients with acceptable procedural risk.

Results

Coronary revascularization of partially viable and viable myocardial territory may improve clinical outcomes by preventing future ischemic, infarct events and further worsening of left ventricular remodeling and function.

Conclusions

When deciding if coronary revascularization is appropriate in a patient with ICM, it is essential to take a patient‐tailored, comprehensive approach incorporating myocardial viability, ischemia, and scar data with others such as procedural risk, and patient's comorbidities.

1.

Viability of myocardium is assessed by different imaging modalities, probing different characteristics of the living myocyte – uptake of radioactive isotope, TC‐99m or Tl‐201 (SPECT MPI), contractile reserve (Dobutamine stress imaging, echo or CMR), metabolic properties (FDG uptake on PET), absence of scar (CMR).

2.

Dysfunctional, viable myocardium as compared to nonviable myocardium carries a better prognosis with appropriate therapy.

3.

Dysfunctional myocardium may not be simplified into a binary state of viable or not. It can be a continuum process, with a myocardial segment in a hybrid state with an intermix of viable myocytes in early to late phases of hibernation and fibrosis.

4.

Nonviable myocardium on Dobutamine Stress Echocardiography or SPECT Nuclear imaging may be partially viable (with varying degrees of fibrosis) or viable with no scar, on CMR.

5.

Coronary revascularization of partially viable or viable myocardium should be considered if the procedural risk is acceptable, as it improves long‐term outcomes by preventing further myocardial ischemia/infarction and possibly improving left ventricular function and remodeling.

The timing of surgical revascularisation in acute myocardial infarction: when should we intervene?

INTRODUCTION

Coronary artery bypass grafting (CABG) is a crucial intervention in acute myocardial infarction (AMI), particularly when AMI is not amenable for management with primary percutaneous coronary intervention (PCI). To optimise outcome in these patients, surgical teams must consider a host of predictive factors, with the most prominent being the timing of CABG. Despite numerous studies exploring timing of CABG following AMI in the past, optimal surgical timing remains controversial. The mortality rates vary with timing of CABG, but confounding factors such as age, impaired pulmonary function, renal insufficiency, and poor left ventricular function may contribute to varied outcomes reported.

EVIDENCE ACQUISITON

An electronic literature search of articles that discussed acute myocardial presentation and urgent in-patient or elective CABG was conducted.

EVIDENCE SYNTHESIS

The evidence was synthesised based on each reported article and their outcomes.

CONCLUSIONS

Current literature suggests multiple factors can guide CABG timing including, type of AMI at initial presentation, distinctive pathological status and patient characteristics. Thus, there is a need for large, multi-centre studies to identify optimal CABG timing in complex coronary artery disease or failed PCI in patients with AMI. Future guidelines should emphasise patient cohorts by taking their risk factors into consideration. As such, a need for greater cardiac screening methods and development of scoring systems can aid in the optimisation of CABG timing.

Delayed Echo Enhancement Imaging to Quantify Myocardial Infarct Size

BACKGROUND

Perfluoropropane droplets formulated from commercial microbubbles exhibit different acoustic characteristics than their parent microbubbles, most likely from enhanced endothelial permeability. This enhanced permeability may permit delayed echo-enhancement imaging (DEEI) similar to delayed enhancement magnetic resonance imaging (DE-MRI). We hypothesized this would allow detection and quantification of myocardial scar.

METHODS

In 15 pigs undergoing 90 minutes of left anterior descending ischemia by either balloon (n = 13) or thrombotic occlusion (n = 2), DE-MRI was performed at 2-24 days postocclusion. Delayed echo-enhancement imaging was performed at 2-4 minutes following an intravenous injection of 1 mL of 50% Definity (Lantheus Medical) compressed into 180 nm droplets; DEEI was attempted in all pigs with single-pulse harmonic imaging at 1.7 transmit/3.4 MHz receive. Myocardial defects observed with DEEI were quantified (percentage of infarct area) and compared with DE-MRI as well as postmortem staining. In six pigs, multipulse low-mechanical index (MI) fundamental nonlinear imaging (FNLI) with intermittent high-MI impulses was performed to determine whether droplet activation within the infarct zone was achievable with a longer pulse duration.

RESULTS

The range of infarct size area by DE-MRI ranged from 0% to 46% of total left ventricular area. Single-pulse harmonic imaging detected a contrast defect that correlated closely with infarct area by DE-MRI (r = 0.81, P = .0001). The FNLI high-MI impulses resulted in droplet activation in both the infarct and normal zones. Harmonic subtraction of the FNLI images resulted in infarct zone enhancement that also correlated closely with infarct size (r = 0.83; P = .04). Droplets were observed on postmortem transmission electron microscopy within myocytes of the infarct and remote normal zone.

CONCLUSION

Intravenously Definity nanodroplets can be utilized to detect and quantify infarct zone at the bedside using DEEI techniques.

Prognostic value of myocardial scar by magnetic resonance imaging in patients undergoing coronary artery bypass graft

BACKGROUND

Previous studies demonstrated that scar tissue assessed by late gadolinium enhancement cardiovascular magnetic resonance imaging (LGE-CMR) is associated with recovery of cardiac function after coronary artery bypass graft (CABG) in patients with a history of myocardial infarction (MI). However, information on the association between myocardial scar at baseline and long-term survival after CABG in these patients is lacking.

METHODS

From April 2010 to May 2013, consecutive patients with multivessel coronary artery disease (CAD, > 70% stenosis in ≥2 vessels) and MI (> 3 months) who underwent LGE-CMR within 1 month prior to isolated CABG were enrolled. Left ventricular functional parameters and scar tissue were assessed by LGE-CMR before surgery. A standard 17-segment model was used for scar quantification. Predictors for cardiovascular events (CVEs) were analyzed.

RESULTS

Of 148 patients who met the study inclusion/exclusion criteria, 140 cases had follow-up data and were included in final analysis. Of the latter, 27 (19.3%) patients suffered CVEs perioperatively or during mean 89.6 ± 12.0 months follow-up. In Cox proportional hazard regression model, the most significant predictor for CVEs after CABG was the number of scar segments on LGE-CMR (Hazard ratio 2.078, 95% Confidence Interval 1.133-3.814, P= 0.018). In Receiver-Operator-Characteristic (ROC) analysis, number of scar segments ≥6 predicted CVEs (sensitivity, 74.1%; specificity, 95.6%; area under the curve [AUC] = 0.934, P < 0.001).

CONCLUSIONS

Scar tissue identified by LGE-CMR appears to be an independent predictor of CVEs after CABG in patients with a history of MI, which might allow preoperative risk stratification.

Evaluation of arterial stiffness in cardiac surgical patients using applanation tonometry

Context:

Applanation tonometry enables the noninvasive analysis of arterial pressure wave morphology. Applanation tonometry provides the augmentation index (AIx, %), an index of arterial stiffness that partially reflects arterial-ventricular (A-V) coupling. In addition, applanation tonometry provides the dP/dt (rate of intraventricular pressure variation over time), which reflects myocardial contractility, and the sub-endocardial viability ratio (SEVR, %), which is an indicator of myocardial oxygen supply and demand. There are no data on how cardiac surgery can modify these tonometry-derived indexes.

Aim:

The aim was to assess changes in AIx, dP/dt, and SEVR in patients undergoing cardiac surgery.

Subjects and Methods:

This observational study was conducted at the University Hospital of Siena. We studied 32 patients before cardiac surgery in intensive care unit (ICU) on admission and at ICU discharge. We measured AIx, dP/dt, and SEVR using applanation tonometry (SphygmoCor). Changes in variables over time were evaluated by analysis of variance for repeated measurements.

Results:

AIx decreased significantly from T1 [28.8%, interquartile range (IQR) 21.6–36.6%] to T2 (16.2% IQR 8.1–22.4%) and T3 (14.5% IQR 7.9–23.6%) (P = 0.01). dP/dt increased significantly from T1 (635 mmHg/ms, IQR 534–756 mmHg/ms) to T3 (751 mmHg/ms, IQR 651–1013 mmHg/ms; P = 0.03). The SEVR was lower at T2 than at T1, but returned toward T1 values by T3.

Conclusions:

Cardiac surgery was associated with an improvement in arterial stiffness, A-V coupling, and myocardial contractility as assessed using applanation tonometry. The results suggest, however, a transient imbalance between myocardial oxygen supply and demand in the immediate postoperative period.

Importance of baseline heart rate as a predictor of cardiac functional recovery in newly diagnosed heart failure with reduced ejection fraction

BACKGROUND

Left ventricular ejection fraction (LVEF) has shown to predict outcomes in patients with heart failure (HF). Left ventricular recovery (LVR) has shown to improve prognosis.

HYPOTHESIS

Guideline-directed medical therapy will predict LVR in patients with HF and reduced LVEF.

METHODS

We studied 244 patients with newly diagnosed HF and an LVEF ≤35%. LVR was defined as an increase in LVEF ≥40%. Patients who experienced LVR were compared with those who had persistent left ventricular dysfunction.

RESULTS

Population characteristics included ischemic etiology, 38.1%; baseline LVEF, 23% ±6%; and mean baseline heart rate (HR), 75 ±13 bpm. Guideline-directed medical therapy was achieved as follows: angiotensin-converting enzyme inhibitors, 74.3%; β-blockers (BB), 95.4%; target dosing of angiotensin-converting enzyme inhibitors, 33.7%; target dosing of BB, 40.2%. LVR occurred in 154/244 patients (63.1%). By multivariable analysis, baseline HR ≤70 bpm was the only independent predictor of LVR (odds ratio: 3.39, 95% confidence interval: 1.5-7.5, P = 0.003). Target dosing of BB therapy was predictive of LVR only in the univariate analysis (odds ratio: 1.9, 95% confidence interval: 1.1-3.4, P = 0.03). Furthermore, the composite endpoint of HF hospitalization or mortality occurred less frequently in those who did vs those who did not achieve target BB doses (5.4% vs 16.7%, respectively; P = 0.023).

CONCLUSIONS

The novel findings of our analysis reveal that the only predictor of LVR in this study was a low baseline HR. Early modulation of HR in newly diagnosed HF patients may increase the rates of LVR.

Cardiac Magnetic Resonance Predictor of Ventricular Function after Surgical Coronary Revascularization

We evaluated echocardiographic changes of left ventricular (LV) function in coronary artery bypass grafting (CABG) patients with LV dysfunction, and examined cardiac magnetic resonance (CMR) parameters associated with improved LV function. Seventy-seven CABG patients presenting with decreased LV ejection fraction (LVEF, ≤ 35%) and who underwent preoperative gadolinium-enhanced CMR were enrolled. A 16-segment model was used to analyze CMR imaging. A viable myocardial segment was defined as ≤ 50% transmural extent of late gadolinium enhancement. Serial echocardiographic examinations were performed preoperatively, pre-discharge (median 6 days), and during postoperative year 1 (median 11 months) in 70 patients. Predictors of absolute increase in LVEF (≥ 5%) and proportional changes in LVEF were analyzed. Serial echocardiography demonstrated that LVEF measured 28.6% ± 5.4% preoperatively, 31.5% ± 8.0% median 6 days, and 42.1% ± 10.5% median 11 months postoperatively. Absolute increase of LVEF was observed in 27 patients at pre-discharge and in 24 patients by median 11 months. Proportional changes in LVEF at postoperative median 6 days and 11 months were 14% ± 28% and 57% ± 45%, respectively. The median number of viable myocardial segments was 14 (range, 9-16) in the 16 segment CMR model. Multivariable models demonstrated that the median number of overall viable myocardial segments (≥ 14) in preoperative CMR was associated with absolute increase (P = 0.046) and proportional changes (P = 0.005) in LVEF. In conclusion, the number of viable myocardial segments (≥ 14) in preoperative CMR predicted LV function improvement after CABG in patients with LV dysfunction.

Scar quantification by cardiovascular magnetic resonance as an independent predictor of long-term survival in patients with ischemic heart failure treated by coronary artery bypass graft surgery

BACKGROUND

Scar burden by late gadolinium enhancement (LGE) cardiovascular magnetic resonance (CMR) is associated with functional recovery after coronary artery bypass surgery (CABG). There is limited data on long-term mortality after CABG based on left ventricular (LV) scar burden.

METHODS

Patients who underwent LGE CMR between January 2003 and February 2010 within 1 month prior to CABG were included. A standard 16 segment model was used for scar quantification. A score of 1 for no scar, 2 for ≤ 50 % and 3 for > 50 % transmurality was assigned for each segment. LV scar score (LVSS) defined as the sum of segment scores divided by 16. All-cause mortality was ascertained by social security death index.

RESULTS

One hundred ninety-six patients met the inclusion criteria. 185 CMR studies were available. History of prior MI was present in 64 % and prior CABG in 5.4 % of patients. Scar was present in 72 % of patients and median LVEF was 38 %. Over a median follow up of 8.3 years, there were 64 deaths (34.6 %). There was no statistically significant difference in mortality between Scar and No-scar groups (37 % versus 29 %). In the group with scar, a lower scar burden (defined either < 4 segments with scar or based on LVSS) was independently associated with increased survival.

CONCLUSION

In patients undergoing surgical revascularization, scar burden is negatively associated with survival in patients with scar. However, there is no difference in survival based on presence or absence of scar alone. CMR prior to CABG adds additional prognostic information.

Natural History and Implantable Cardioverter-Defibrillator Implantation After Revascularization for Stable Coronary Artery Disease With Depressed Ejection Fraction

BACKGROUND

Following revascularization, most payors require 3 months of medical therapy, followed by left ventricular ejection fraction (LVEF) reassessment, before implantable cardioverter-defibrillator (ICD) implantation possibly contributing to incomplete follow-up and suboptimal utilization of ICD therapy. The natural history of these patients, and their fate regarding ICD implantation, is unknown.

HYPOTHESIS

We hypothesized that a waiting period after revascularization for stable CAD results in missed opportunities to provide care with regard to ICD implantation.

METHODS

We followed patients with LVEF ≤ 35% and no ICD who underwent revascularization (coronary artery bypass grafting [CABG] or percutaneous coronary intervention [PCI]) for stable CAD. Follow-up used chart review and scripted telephone interviews.

RESULTS

Among 3164 revascularized patients (2198 [69%] PCI, 966 [31%] CABG), only 62 (2%; 33 [53%] male, age 67 ± 12 y, LVEF 28% ± 6%) had stable CAD, depressed LVEF, and no ICD. Over 35 ± 19 months, 35 (56%) of these 62 patients were no longer candidates for ICD based on improved LVEF, 14 (23%) received an ICD, 5 (8%) declined ICD despite physician recommendation, 3 (5%) were not offered ICD despite continued eligibility, 2 (3%) died, 1 (2%) was not a candidate due to substance abuse, and 1 (2%) had ICD implantation temporarily deferred. Only 1 (2%) was lost to follow-up.

CONCLUSIONS

Following revascularization for stable CAD with depressed LVEF, ≥50% of patients' ventricular function improved enough to make ICD implantation unnecessary. A waiting period after revascularization prior to ICD implantation appears appropriate and does not significantly negatively impact follow-up or the rate of appropriate ICD implantation.