Residual functional SYNTAX score by quantitative flow ratio and improvement of exercise capacity after revascularization.

OBJECTIVES: This study aimed to evaluate the association between improvement in exercise capacity and functional completeness of revascularization, determined by residual functional SYNTAX score (rFSS), which is the sum of residual SYNTAX score of the vessels with post- percutaneous coronary intervention (PCI) quantitative flow ratio (QFR) ≤0.80. BACKGROUND: In patients with stable ischemic heart disease (SIHD), the efficacy of PCI in improving exercise capacity has been under debate and the differential effect of PCI for exercise capacity, according to functional completeness of revascularization, has not been evaluated. METHODS: Among patients enrolled in the QFR multicenter registry, 110 patients who underwent routine exercise treadmill tests before and after PCI were analyzed. Patients were classified into functional complete revascularization (CR) group (rFSS = 0) and functional incomplete revascularization (IR) group (rFSS ≥ 1). Increase of exercise time after PCI was compared between the two groups. Improvement of exercise capacity was defined as ≥10% increase of exercise time after PCI. RESULTS: Functional CR was achieved in 79 patients (71.8%), otherwise classified as functional IR in 31 patients (28.2%) without differences in baseline characteristics including medication profiles. Increase of exercise time was significantly associated with increase of 3-vessel QFR (sum of QFRs in all three vessels; r = .198, p = .038) and rFSS (r = -.312, p < .001), but not with decrease of SYNTAX score (r = .097, p = .313). The rFSS showed significantly higher c-index to predict the improvement of exercise capacity after PCI than increase of 3-vessel QFR or decrease of SYNTAX score (0.722 vs. 0.627 vs. 0.492, respectively, p < 0.001). Patients with functional CR, defined by rFSS, showed significantly higher absolute and relative increase in exercise time than those with functional IR (97.7 s vs. 12.5 s, p < .001; 25.4% vs. 3.6%, p = .001). Functional CR was an independent predictor for improvement of exercise capacity after PCI (adjusted OR 4.656, 95% CI 1.678-12.920, p = .002). CONCLUSIONS: Integrated anatomic and functional scoring system (rFSS) was significantly associated with improvement of exercise capacity after PCI. SIHD patients with functional CR, defined by rFSS, showed significantly higher exercise capacity after PCI than those with functional IR.

Functional angiography-derived index of microcirculatory resistance validated with microvascular obstruction in cardiac magnetic resonance after STEMI.

INTRODUCTION AND OBJECTIVES: The index of microcirculatory resistance (IMR) measured after primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI) is associated with microvascular obstruction (MVO) and adverse clinical events. To evaluate MVO after successful primary PCI for STEMI without pressure wires or hyperemic agents, we investigated the feasibility and usefulness of functional angiography-derived IMR (angio-IMR). METHODS: The current study included a total of 285 STEMI patients who underwent primary PCI and cardiac magnetic resonance (CMR). Angio-IMR of the culprit vessel after successful primary PCI was calculated using commercial software. MVO, infarct size, and myocardial salvage index were assessed using CMR, which was obtained a median of 3.0 days [interquartile range, 3.0-5.0] after primary PCI. RESULTS: Among the total population, 154 patients (54.0%) showed elevated angio-IMR (> 40 U) in the culprit vessel. MVO was significantly more prevalent in patients with angio-IMR> 40 U than in those with angio-IMR ≤ 40 U (88.3% vs 32.1%, P <.001). Infarct size, extent of MVO, and area at risk were significantly larger in patients with angio-IMR> 40 U than in those with angio-IMR ≤ 40 U (P <.001 for all). Angio-IMR showed a significantly higher discriminatory ability for the presence of MVO than thrombolysis in myocardial infarction flow grade or myocardial blush grade (area under the curve: 0.821, 0.504, and 0.496, respectively, P <.001). CONCLUSIONS: Angio-IMR was significantly associated with CMR-derived infarct size, extent of MVO, and area at risk. An elevated angio-IMR (> 40 U) after primary PCI for STEMI was highly predictive of the presence of MVO in CMR. This trial was registered at ClnicalTrialsgov (Identifier: NCT04828681).

Functional Coronary Angiography-Derived Index of Microcirculatory Resistance in Patients With ST-Segment Elevation Myocardial Infarction.

OBJECTIVES: The aim of this study was to evaluate the diagnostic accuracy and prognostic implications of angiography-derived index of microcirculatory resistance (angio-IMR) in patients with ST-segment elevation myocardial infarction (STEMI). BACKGROUND: The index of microcirculatory resistance (IMR) is a reliable invasive measure of coronary microvascular dysfunction in patients with STEMI. A functional coronary angiography-derived method to estimate IMR is a wire- and hyperemic agent-free alternative to IMR. METHODS: The study population consisted of 2 independent cohorts. The diagnostic cohort comprised patients with IMR from the culprit vessel immediately after successful primary percutaneous coronary intervention (n = 31). The prognostic cohort was patients with STEMI who were successfully treated with primary percutaneous coronary intervention and followed for 10 years from the index procedure (n = 309). Angio-IMR was calculated using computational flow and pressure simulation. The primary outcome was a composite of cardiac death and readmission for heart failure over 10 years of follow-up. RESULTS: In the diagnostic cohort, angio-IMR correlated well with IMR (R = 0.778; P < 0.001). Sensitivity, specificity, accuracy, and area under the curve of angio-IMR to predict IMR >40 U were 75.0%, 84.2%, 80.6%, and 0.899 (95% confidence interval: 0.786-0.949), respectively. In the prognostic cohort, patients with angio-IMR >40 U showed significantly higher risk for cardiac death or readmission for heart failure than did those with angio-IMR ≤40 U (46.7% vs 16.6%; adjusted hazard ratio: 2.909; 95% CI: 1.670-5.067; P < 0.001). Angio-IMR >40 U was an independent predictor of cardiac death or readmission for heart failure (hazard ratio: 2.173; 95% CI: 1.157-4.079; P = 0.016) and showed incremental prognostic value compared with a model with clinical risk factors only (C index = 0.726 vs 0.666 [P < 0.001], net reclassification index = 0.704 [P < 0.001]). CONCLUSIONS: Angio-IMR showed high correlation and diagnostic accuracy to predict IMR. Patients with STEMI with angio-IMR >40 U showed a significantly higher risk for cardiac death or readmission for heart failure than those with preserved angio-IMR values. (Prognostic Implication of Angiography-Derived IMR in STEMI Patients; NCT04628377).

Comparison of Exercise Performance and Clinical Outcome Between Functional Complete and Incomplete Revascularization.

BACKGROUND AND OBJECTIVES: Although percutaneous coronary intervention (PCI) is recommended to improve symptoms in patients with stable ischemic heart disease (SIHD), improvement of exercise performance is controversial. This study aimed to investigate changes in exercise duration after PCI according to functional completeness of revascularization by comparing pre- and post-PCI exercise stress test (EST). METHODS: Patients with SIHD were enrolled from a prospective PCI registry, and divided into 2 groups: 1) functional complete revascularization (CR) group had a positive EST before PCI and negative EST after PCI, 2) functional incomplete revascularization (IR) group had positive EST before and after PCI. Primary outcome was change in exercise duration after PCI and secondary outcome was major adverse cardiac events (MACE, a composite of any death, any myocardial infarction, and any ischemia-driven revascularization) at 3 years after PCI. RESULTS: A total of 256 patients (149 for CR group, and 107 for IR group) were eligible for analysis. Before PCI, exercise duration was not significantly different between the functional CR and IR groups (median 540 [interquartile range; IQR, 414, 602] vs. 480 [402, 589] seconds, p=0.091). After PCI, however, the CR group had a significantly higher increment of exercise duration than the IR group (median 62.0 [IQR, 12.0, 141.0] vs. 30.0 [-11.0, 103.5] seconds, p=0.011). The functional CR group also had a significantly lower risk of 3-year MACE (6.2% vs. 26.1%; adjusted hazard ratio, 0.19; 95% confidence interval, 0.09-0.41; p<0.001). CONCLUSIONS: Functional CR showed a higher increment of exercise duration than functional IR.

What Is the Optimal Exercise Prescription for Patients With Dilated Cardiomyopathy in Cardiac Rehabilitation? A SYSTEMATIC REVIEW.

PURPOSE: Dilated cardiomyopathy (DCM) is 1 of the major causes of advanced heart failure. However, relatively little is known about the effects of exercise specifically in patients with DCM. This purpose of this literature review was to identify optimal exercise training programming for patients with DCM. METHODS: A systematic review was conducted by 3 clinical specialists and the level of evidence of each study was rated using Sackett's levels of evidence. Multiple databases (PubMed Central, EMBASE, and EBSCO) were searched with the inclusion criteria of articles published in English. RESULTS: A total of 4544 studies were identified using the search strategy, of which 4 were included in our systematic review. The exercise frequency of the reviewed studies ranged from 3 to 5 times/wk, and exercise intensity was prescribed within a range from 50% to 80% of oxygen uptake reserve. Exercise time was as high as 45 min by the final month of the exercise prescription. Exercise type was mainly aerobic exercise and resistance training. The average improvement of exercise capacity was 19.5% in reviewed articles. Quality of life also improved after intervention. CONCLUSIONS: According to this systematic review of the literature, data related to exercise therapy specifically for patients with DCM are scarce and exercise interventions in articles reviewed were prescribed differently using the FITT (frequency, intensity, time, and type) principle. Exercise intensity tailored to individual exercise capacity should be used for optimal exercise prescriptions that are safe and efficacious in patients with DCM.

Clinical outcomes of inpatient cardiac rehabilitation for patients with treated left ventricular assist device in Korea: 1-year follow-up.

In Korea, the first patient with a left ventricular assist device (LVAD) for destination therapy had successful implantation of a continuous-flow model in 2012. We investigated the safety and efficacy of exercise therapy with LVAD implantation 15 Korean patients. We retrospectively reviewed 15 patients (mean age, 67.4±11.6 years; 10 males, 5 female, left ventricular ejection fraction 23.6%±7.1%), including 4 with implanted continuous-flow and 11 an axial-flow LVAD. The New York Heart Association functional classification, ejection fraction, and quality of life were obtained. Survival rate, adverse events, admission rates, and enrollment rates in cardiac rehabilitation were investigated. Survival at 6 and 12 months was 100% and 89%, respectively. The New York Heart Association functional classification improved from 3.4±0.5 to 2.3±0.05 at 12 months postoperatively (P<0.0001). The ejection fraction significantly increased from 23.6%±7.2% on the preoperative day to 35.4%±14.2% at 1 year (P<0.0018). The quality of life was also improved at 1 year (P<0.0001). The most common adverse events were bleeding (56%) and dyspnea (44%). The number of admissions was 3.2 per patient-year. LVAD therapy is a safe and effective treatment option with exercise intervention for Korean patients waiting for heart transplantation or those who were ineligible for heart transplantation. A larger study with longer follow-up is needed to determine details clinical outcomes after LVAD.

Comparison of long-term clinical outcomes between revascularization versus medical treatment in patients with silent myocardial ischemia.

BACKGROUND: There have been limited and conflicting results regarding the prognostic impact of revascularization treatment on the long-term clinical outcomes of silent ischemia. The current study aimed to determine whether revascularization treatment compared with medical treatment (MT) alone reduces long-term risk of cardiac death of asymptomatic patients with objective evidence of inducible myocardial ischemia. METHODS: A total of 1473 consecutive asymptomatic patients with evidence of inducible myocardial ischemia were selected from a prospective institutional registry. All patients showed at least 1 epicardial coronary stenosis with ≥50% diameter stenosis in coronary angiography. Patients were classified according to their treatment strategies. The primary outcome was cardiac death up to 10 years. RESULTS: Among the total population, 709 patients (48.1%) received revascularization treatment including percutaneous coronary intervention (PCI, n = 558) or coronary artery bypass graft surgery (CABG, n = 151), with the remaining patients (764 patients, 51.9%) receiving MT alone. During the follow-up period, the revascularization treatment group showed a significantly lower risk of cardiac death compared with the MT alone group (25.4% vs. 33.7%, HR 0.624, 95%CI 0.498-0.781, p < 0.001). Among revascularized patients, patients with negative non-invasive stress test results after revascularization showed significantly lower risk of cardiac death compared to those with residual myocardial ischemia (8.9% vs. 18.7%, HR 0.406, 95% CI 0.175-0.942, p = 0.036). CONCLUSIONS: In patients with silent myocardial ischemia, revascularization treatment was associated with significantly lower long-term risk of cardiac death compared with the MT alone group. The current results support contemporary practice of ischemia-directed revascularization, even in patients with silent myocardial ischemia.

High-Intensity Versus Non-High-Intensity Statins in Patients Achieving Low-Density Lipoprotein Cholesterol Goal After Percutaneous Coronary Intervention.

Background Whether use of high-intensity statins is more important than achieving low-density lipoprotein cholesterol ( LDL -C) target remains controversial in patients with coronary artery disease. We sought to investigate the association between statin intensity and long-term clinical outcomes in patients achieving treatment target for LDL -C after percutaneous coronary intervention. Methods and Results Between February 2003 and December 2014, 1746 patients who underwent percutaneous coronary intervention and achieved treatment target for LDL -C (<70 mg/dL or >50% reduction from baseline level) were studied. We classified patients into 2 groups according to an intensity of statin prescribed after index percutaneous coronary intervention: high-intensity statin group (atorvastatin 40 or 80 mg, and rosuvastatin 20 mg, 372 patients) and non-high-intensity statin group (the other statin treatment, 1374 patients). The primary outcome was a composite of cardiac death, myocardial infarction, or stroke. Difference in time-averaged LDL -C during follow-up was significant, but small, between the high-intensity statin group and non-high-intensity statin group (59±13 versus 61±12 mg/dL; P=0.04). At 5 years, patients receiving high-intensity statins had a significantly lower incidence of the primary outcome than those treated with non-high-intensity statins (4.1% versus 9.9%; hazard ratio, 0.42; 95% confidence interval, 0.23-0.79; P<0.01). Results were consistent after propensity-score matching (4.2% versus 11.2%; hazard ratio, 0.36; 95% confidence interval, 0.19-0.69; P<0.01) and across various subgroups. Conclusions Among patients achieving treatment target for LDL -C after percutaneous coronary intervention, high-intensity statins were associated with a lower risk of major adverse cardiovascular events than non-high-intensity statins despite a small difference in achieved LDL -C level.

The Effect of Preoperative Cognitive Behavior and Exercise Therapy for a Patient With an Implanted Left Ventricular Assist Device in Korea.

Left ventricular assist devices (LVADs) are used in patients with progressive heart failure symptoms to provide circulatory support. Patients with LVADs are referred to inpatient cardiac rehabilitation to prevent postoperative complications and improve aerobic capacity and quality of life. Preoperative exercise therapy for cardiac patients is an emerging treatment modality, and several studies have reported that it improves postoperative outcomes, such as length of hospital stay and postoperative complications. This case report describes the benefits of preoperative cognitive behavioral and exercise therapy in a Korean patient undergoing LVAD implantation. LEVEL OF EVIDENCE: V.

Inpatient cardiac rehabilitation programs' exercise therapy for patients undergoing cardiac surgery: National Korean Questionnaire Survey.

Inpatient cardiac rehabilitation (ICR) has been commonly conducted after cardiac surgery in many countries, and has been reported a lots of results. However, until now, there is inadequacy of data on the status of ICR in Korea. This study described the current status of exercise therapy in ICR that is performed after cardiac surgery in Korean hospitals. Questionnaires modified by previous studies were sent to the departments of thoracic surgery of 10 hospitals in Korea. Nine replies (response rate 90%) were received. Eight nurses and one physiotherapist completed the questionnaire. Most of the education on wards after cardiac surgery was conducted by nurses. On postoperative day 1, four sites performed sitting on the edge of bed, sit to stand, up to chair, and walking in the ward. Only one site performed that exercise on postoperative day 2. One activity (stairs up and down) was performed on different days at only two sites. Patients received education preoperatively and predischarge for preventing complications and reducing muscle weakness through physical inactivity. The results of the study demonstrate that there are small variations in the general care provided by nurses after cardiac surgery. Based on the results of this research, we recommended that exercise therapy programs have to conduct by exercise specialists like exercise physiologists or physiotherapists for patients in hospitalization period.

Glycemic Control Status After Percutaneous Coronary Intervention and Long-Term Clinical Outcomes in Patients With Type 2 Diabetes Mellitus.

BACKGROUND: Data on the association between glycemic control after percutaneous coronary intervention and clinical outcomes are limited and controversial in diabetic patients. METHODS AND RESULTS: We studied 980 patients with type 2 diabetes mellitus undergoing percutaneous coronary intervention using drug-eluting stents. Based on 2-year glycosylated hemoglobin A (HbA1c) levels, we divided patients into 2 groups of HbA1c<7.0 (n=489) and HbA1c≥7.0 (n=491). Propensity score-matched analysis was performed in 322 pairs. The primary outcome was major adverse cardiac and cerebrovascular events (MACCE), defined as a composite of cardiac death, myocardial infarction, repeat revascularization, or stroke. Median follow-up duration was 5.4 years. The 7-year incidence of MACCE was lower in the HbA1c<7.0 group than in the HbA1c≥7.0 group (26.9% versus 40.3%; adjusted hazard ratio, 0.75; 95% confidence interval, 0.57-0.98; P=0.03). After propensity score matching, the 7-year incidence of MACCE was still lower in the HbA1c<7.0 group than in the HbA1c≥7.0 group (27.5% versus 37.4%; hazard ratio, 0.71; 95% confidence interval, 0.52-0.97; P=0.03), mainly because of a reduction in repeat revascularization (19.9% versus 29.5%; hazard ratio, 0.66; 95% confidence interval, 0.47-0.93; P=0.02). In subgroup analyses, the benefit of glycemic control for MACCE was more prominent in patients with residual SYNTAX score (Synergy Between PCI With Taxus and Cardiac Surgery) >4 than in those with the residual SYNTAX score ≤4 (Pinteraction=0.004). CONCLUSIONS: HbA1c<7.0 measured 2 years after percutaneous coronary intervention was associated with a reduced rate of MACCE. Our data suggest that high HbA1c levels 2 years after percutaneous coronary intervention may identify a population at increased risk of adverse events, especially repeat revascularization.