Hypertrophic Obstructive Cardiomyopathy: Discrepancy Between Hemodynamic Measurements in the Cardiac Laboratory and Operating Room Is to Be Expected.

OBJECTIVES: It is not uncommon to observe some discrepancy in hemodynamic values characterizing left ventricular outflow tract (LVOT) obstruction preoperatively and in the operating room in patients with hypertrophic obstructive cardiomyopathy. Interpretation of this discrepancy can be challenging. To clarify the extent of the discrepancy, the authors compared hemodynamic variables in patients undergoing septal myectomy at the time of preoperative and intraoperative evaluation. DESIGN: Retrospective study. SETTING: Single academic medical center. INTERVENTIONS: Medical records review, study group-173 patients. MEASUREMENTS AND MAIN RESULTS: While there was no statistically significant difference in resting peak LVOT gradients by preoperative transthoracic echocardiography (TTE) compared to intraoperative transesophageal echocardiography (46 mmHg [19-87 mmHg] v 36 mmHg [16-71 mmHg], p = 0.231), the former were higher compared to direct needle-resting LVOT gradient measurements before myectomy (49 mmHg [19-88 mmHg] v 32 mmHg [14-67 mmHg], p = 0.0022). The prevalence of systolic anterior motion was high (94.6% v 91.6%, P = 1.000) both on pre- and intraoperative evaluation. The incidence of moderate/severe mitral was higher intraoperatively (p < 0.0001). Pulmonary artery systolic pressures measured by pulmonary artery catheter provided higher values compared to preoperative TTE estimate (39 mmHg [34-45 mmHg] v 34 mmHg [28-41 mmHg], p < 0.0001). CONCLUSIONS: Discrepancy between hemodynamic measurements in the cardiac laboratory and operating room is common and generally should not affect planned patients' care. These changes in hemodynamics might be explained by preoperative fasting, anesthetic agents, volume shifts while supine, and positive-pressure ventilation, as well as the difference in measurement techniques.

Thrombin Generation and Antithrombin Activity in Infants Undergoing Cardiopulmonary Bypass-An Exploratory Study.

OBJECTIVES: Coagulopathic bleeding is a major complication of pediatric cardiac surgery. Investigating perioperative dynamics of thrombin generation and antithrombin (AT) activity might provide more insight into the underlying mechanisms of coagulopathy. This can help develop a targeted hemostatic approach in the future. The authors hypothesized that there is a decline in both thrombin generation and AT activity in infants undergoing cardiopulmonary bypass (CPB). DESIGN: Prospective observational study. SETTING: Single academic medical center. PARTICIPANTS: Infants <10 kg of weight undergoing cardiac surgery with CPB. INTERVENTIONS: Blood specimen collection and testing. MEASUREMENTS AND RESULTS: The authors performed assays of thrombin generation and AT activity on the samples of platelet-poor plasma of 25 infants, repeating them at 3 points: before CPB and heparinization, after separation from CPB and protamine administration, and after chest closure. The authors observed a statistically significant decline in thrombin generation shortly after separation from CPB compared with baseline. The geometric mean for lag time was prolonged (4.0 v 5.5 minutes, p = 0.013), and peak thrombin and the net amount of generated thrombin declined almost 3-fold (80.7 v 25.1 nmol, p < 0.001; 1264 v 476 nmol, p < 0.001, respectively). This was accompanied by a decline in AT activity (59.8 v 50.1, p = 0.001). After platelet and cryoprecipitate transfusion, at the case conclusion AT activity had recovered marginally (59.8 v 55.4, p = 0.042), but thrombin generation remained reduced. CONCLUSIONS: In pediatric patients <10 kg undergoing cardiac surgery with CPB, thrombin generation and AT activity decline and do not recover completely after transfusion of platelets and cryoprecipitate.

Perioperative Use of Coagulation Factor Concentrates in Patients Undergoing Cardiac Surgery.

Coagulopathy and bleeding are common in patients undergoing cardiac surgery, with a perioperative transfusion rate in excess of 50%. The mechanism of coagulopathy associated with cardiac surgery using cardiopulmonary bypass is multifactorial. Historically, coagulation factor-mediated bleeding in such instances has been treated with allogeneic plasma transfusion. Coagulation factor concentrate use for treatment of hemophilia, congenital factor deficiencies and, more recently, emergency warfarin reversal is common. Formulations of factor concentrates include single and multifactor concentrates and both human and recombinant-derived products. Off-label use of factor concentrates for coagulopathy and bleeding associated with cardiac surgery has been described for decades; however, sound clinical research with regard to this practice is limited. This review highlights the literature discussing the use of factor concentrates in patients undergoing cardiac surgery and provides an overview of reasonable uses or lack thereof for factor concentrates in clinical practice.

Three-dimensional versus two-dimensional echocardiographic assessment of functional mitral regurgitation proximal isovelocity surface area.

BACKGROUND: The geometric shape of the mitral regurgitation (MR) proximal isovelocity surface area (PISA) is conventionally assumed to be a hemisphere (HS). However, in functional MR, PISA is frequently neither an HS nor a hemiellipse (HE) but is often asymmetric and crescent shaped. We used 3-dimensional transesophageal echocardiographic (3D TEE), full-volume data sets to directly measure the PISA and subsequently compared calculated values of effective regurgitant orifice area (EROA) with conventional 2D TEE techniques. EROA calculations from all PISA measurements were finally compared with the cross-sectional area at the vena contracta, a well-validated reference measure of the functional MR orifice area. METHODS: Twenty-four cardiac surgical patients with functional MR, who underwent routine intraoperative TEE examinations with a 3D matrix array probe (X7-2t; IE33; Philips Healthcare, Inc., Andover, MA) were retrospectively evaluated for MR severity using quantitative 2D and 3D TEE-derived techniques. Conventional 2D TEE methods were used to estimate PISA assuming an HS shape and an HE shape. In addition, direct measurement of the 3D PISA was obtained (QLab, Philips Healthcare, Inc.) from corresponding full-volume, color-flow Doppler data sets. EROAs calculated from HS- and HE-PISA techniques were compared with the same values obtained from 3D TEE PISAs. EROAs obtained from all 3 PISA techniques were subsequently compared with vena contracta area. RESULTS: Three-dimensional PISA was significantly larger than both HS-PISA and HE-PISA (mean ± SD: 4.65 ± 2.03 cm² vs 2.10 ± 1.58 cm² and 2.75 ± 1.42 cm²; both P < 0.0001), respectively. HE-PISA was also larger than HS-PISA (P = 0.042). In addition, 3D EROA was larger than both HS- and HE-acquired EROAs (mean ± SD: 0.44 ± 0.21 vs 0.19 ± 0.12 cm² and 0.26 ± 0.14; both P < 0.0001), respectively, while HE-EROA was larger than HS-EROA (P = 0.024). Vena contracta area correlated well with 3D EROA (Spearman r = 0.865), HS-EROA (Spearman r = 0.820; P < 0.001) and HE-EROA (Spearman r = 0.819). However, the difference between vena contracta area and 3D EROA was significantly less than the differences between vena contracta area and either 2D HS- or 2D HE-EROA (P < 0.0001). CONCLUSIONS: Quantitative assessment of functional MR severity by 3D TEE may be superior to 2D methods by permitting more direct measures of PISA. Two-dimensional TEE techniques for assessing functional MR severity that rely on an HS- or HE-PISA shape may underestimate the EROA due to geometric assumptions that do not account for asymmetry.

National In-Hospital Outcomes of Mechanical Mitral Valve Replacement in the Pediatric Population.

Background: National data about the outcomes of children undergoing mechanical mitral valve replacement (m-MVR) are scarce. Methods: A retrospective review of hospitalizations from the Kids' Inpatient Database was performed for patients ≤18 years of age in the United States. A total of 500 patients underwent m-MVR in 2009, 2012, 2016, and 2019. Patients with single ventricle physiology were excluded (n = 13). These patients were categorized into three groups according to age: neonates (<1 month, n = 20), infants (1-12 months, n = 76 patients), and children (1-18 years, n = 404). Outcomes were compared between the three groups. Results: The proportion of m-MVR involving children undergoing MV procedures (repair and replacement) has increased from 17.3% in 2009 to 30.8% in 2019 (Ptrend < .01). History of cardiac surgery was present in 256 patients (51.2%). Concomitant procedures were performed in 119 patients (23.8%). Intra- or postoperative extracorporeal membrane oxygenation was required in 19 patients (3.8%). The overall in-hospital mortality was 4.8% and was significantly higher in neonates and infants compared with older children (10% vs 11.8% vs 3.2%, P = .003). The length of hospital stay was longer in the neonatal group (median, 57 days, interquartile range, [24.8-90] vs 29.5 days [15.5-61] vs 10 days [7-18], P < .01). Nonhome discharges were more common in neonates and infants (40% vs 36.8% vs 13.1%, P < .01). Conclusion: Mechanical mitral valve replacement is increasingly performed over time with acceptable in-hospital morbidity and mortality, especially in older children and adolescents. Neonates and infants are associated with worse hospital survival, prolonged hospitalization, and significant rates of nonhome discharges.

Delayed Sternal Closure vs Emergency Sternal Reopening in Adults With Congenital Heart Disease.

BACKGROUND: Limited data exist regarding outcomes of delayed sternal closure (DSC) in adults with congenital heart disease (ACHD). METHODS: We reviewed 159 ACHD patients undergoing cardiac operation from 1993 to 2023 who required DSC (open sternum at the end of operation, n = 112) or sternum emergently reopened (n = 47). Regression models were performed to determine factors associated with outcomes. RESULTS: Of 112 patients undergoing DSC, 87 patients (77.6%) underwent DSC ≤4 days and 25 patients (22.3%) >4 days. The most common operations were valve (n = 35 [31.2%]), aortic (n = 33 [29.4%]), and right ventricular outflow tract procedures (n = 23 [20.5%]). Median time to chest closure was 2 days (interquartile range, 1-5 days). Apart from sex, baseline characteristics were similar between DSC groups. A stepwise increase in early mortality was observed from DSC ≤4 days to DSC >4 days (6.8% vs 32%), as well as the incidence of early complications, except sternal infection. Risk factors associated with early mortality were age (P = .02), DSC >4 days (P < .001), hemodynamic indication (P = .03), and single ventricle (P = .02). On multivariable analysis, lower ejection fraction (P = .04), hemodynamic indication (P = .02), single ventricle (P = .004), and diabetes mellitus (P = .03) were predictors of prolonged time to chest closure. Among hospital survivors, late survival was similar between patients undergoing DSC ≤4 days vs >4 days (P = .48). CONCLUSIONS: A brief duration of DSC in ACHD patients is associated with low morbidity and mortality. Higher early mortality and complications were observed among patients who did not achieve chest closure within 4 days.

Systemic Atrioventricular Valve Surgery in Patients With Congenitally Corrected Transposition of the Great Vessels.

BACKGROUND: Limited data exist regarding the long-term outcomes of systemic atrioventricular valve (SAVV) intervention (morphologic tricuspid valve) in congenitally corrected transposition (ccTGA). OBJECTIVES: The goal of this study was to evaluate the mid- and long-term outcomes of SAVV surgery in ccTGA. METHODS: We performed a retrospective review of 108 ccTGA patients undergoing SAVV surgery from 1979 to 2022. The primary outcome was a composite endpoint of mortality, cardiac transplantation, or ventricular assist device implantation. The secondary outcome was long-term systemic right ventricular ejection fraction (SVEF). Cox proportional hazard and linear regression models were used to analyze survival and late SVEF data. RESULTS: The median age at surgery was 39.5 years (Q1-Q3: 28.8-51.0 years), and the median preoperative SVEF was 39% (Q1-Q3: 33.2%-45.0%). Intrinsic valve abnormality was the most common mechanism of SAVV regurgitation (76.9%). There was 1 early postoperative mortality (0.9%). Postoperative complete heart block occurred in 20 patients (18.5%). The actuarial 5-, 10-, and 20-year freedom from death or transplantation was 92.4%, 79.1%, and 62.9%. The 10- and 20-year freedom from valve reoperation was 100% and 93% for mechanical prosthesis compared with 56.6% and 15.7% for bioprosthesis (P < 0.0001). Predictors of postoperative mortality were age at operation (P = 0.01) and preoperative SVEF (P = 0.04). Preoperative SVEF (P < 0.001), complex ccTGA (P = 0.02), severe SAVV regurgitation (P = 0.04), and preoperative creatinine (P = 0.003) were predictors of late postoperative SVEF. CONCLUSIONS: SAVV surgery remains a valuable option for the treatment of patients with ccTGA, with low early mortality and satisfactory long-term outcomes, particularly in those with SVEF ≥40%. Timely referral and accurate patient selection are the keys to better long-term outcomes.

Aortic valve replacement in the elderly: determinants of late outcome.

BACKGROUND: Few data exist on long-term outcomes of elderly patients after aortic valve replacement. We evaluated latest follow-up information for patients ≥70 years of age after aortic valve replacement. METHODS AND RESULTS: Late overall survival of 2890 consecutive patients ≥70 years of age who underwent aortic valve replacement between January 1993 and December 2007 was reviewed retrospectively, analyzed, and stratified by preoperative and intraoperative variables. Observed 5-, 10-, and 15-year late postoperative survival was lower than generally expected (68%, 34%, and 8% versus 70%, 42%, and 20%, respectively; P<0.001). Independent predictors of late death included older age, renal failure, diabetes mellitus, stroke, myocardial infarction, immunosuppression, prior coronary artery bypass grafting, implanted pacemaker, lower ejection fraction, hypertension, and New York Heart Association class III or IV. After stratification by age-comorbidity risk score, 10-year survival for the lowest-risk group (n=946 [33%]) was similar to expected survival (55% versus 55%; P=0.50), but for the highest-risk group (n=564 [20%]), survival was significantly lower than expected (9% versus 26%; P<0.001). For 229 pairs of propensity-matched patients with mechanical or biological prostheses, survival was not significantly different (67%, 40%, and 19% versus 71%, 45%, and 7% at 5, 10, and 15 years, respectively; P=0.81). Structural deterioration of bioprostheses occurred in 64 patients (2.4%). CONCLUSIONS: Survival of elderly patients after aortic valve replacement is influenced by age and preoperative comorbidities; 33% at lowest risk had overall survival similar to that of an age- and sex-matched general population. There was no sufficient evidence that valve type affected survival. Structural deterioration of aortic bioprostheses was rare.

Outcomes of Primary vs Secondary Delayed Sternal Closure in Pediatric Cardiac Surgery.

BACKGROUND: Delayed sternal closure (DSC) is a management strategy for hemodynamic instability and severe coagulopathy after complex congenital heart surgery. We hypothesized that DSC results in better outcomes than perioperative sternal reopening. METHODS: We reviewed patients aged <18 years old undergoing cardiac surgery 2007-2017 at our institution. A total of 179 patients (3.8%) had primary DSC (PDSC, sternum left open after initial operation) and 45 patients (0.9%) had secondary DSC (SDSC, sternum closed primarily and reopened perioperatively). Perioperative characteristics and outcomes among PDSC ≤2 days (98 patients), PDSC >2 days (81 patients), and SDSC (45 patients) were analyzed. RESULTS: Median age was 120 days (range, 3-6553 days) and median DSC duration was 2 days (range, 1-60 days). The PDSC >2 days group was the youngest group, and the distribution of procedures was different between groups. Indications for DSC were hemodynamic instability in 152 patients (67.9%) and severe coagulopathy in 33 patients (14.7%), with no difference between groups (P = .141). Extracorporeal membrane oxygenation use was higher in the PDSC >2 days group than the other groups (47.5% vs 7.1%, P < .01 and 47.5% vs 28.9%, P = .02), respectively. Operative mortality was higher in SDSC compared to the other groups (17.8% vs 0% for PDSC ≤2 and 6.2% for PDSC >2 days, P < .01). Hospital stay was longer in SDSC (57 ± 7 days) than PDSC ≤2 days (22 ± 5 days) and PDSC >2 days (44 ± 6, P = .01). Survival was better in PDSC regardless of duration than SDSC. CONCLUSIONS: PDSC demonstrated better outcomes than SDSC. Sternal reopening can be life-saving, but, when anticipated, PDSC can yield better outcomes.

Bidirectional Cavopulmonary Shunt for Right Ventricular Unloading.

BACKGROUND: Right-sided heart failure remains a challenge in the care of congenital heart disease patients, both those with right ventricular dilation and dysfunction and those with right ventricular hypoplasia. Two strategies for treatment are atrial septal fenestration and bidirectional cavopulmonary shunt (BCPS). METHODS: This review details the strategies for right ventricular unloading, with summaries of pertinent data and commentaries on the subject. RESULTS: While atrial septal fenestration provides right ventricular unloading and can be appropriate in cases of moderate right ventricular dysfunction and dilation, this unloading is not as substantial as a BCPS. A BCPS more effectively unloads the right ventricle, provides preload to the left ventricle, and can significantly improve ventricular-ventricular interactions. A BCPS is often appropriate in cases of severe right ventricular dysfunction and dilation, if factors favorable for BCPS circulation are in place. Certain anatomic and physiologic factors assessed both preoperatively and intraoperatively help guide the decision regarding which patient may benefit from right ventricular unloading and which technique is optimal. CONCLUSIONS: When used strategically in select patients, BCPS and atrial-level fenestration are effective in managing right ventricular failure in congenital heart disease patients. Preoperative imaging and intraoperative anatomic and physiologic factors help guide the appropriate management for a given patient.

Risk factors and progression of systolic anterior motion after mitral valve repair.

OBJECTIVES: The phenomenon of systolic anterior motion (SAM) of the mitral valve (MV) was discovered 50 years ago, but to date only a few studies have identified risk factors for SAM following mitral repair. There are limited data on the necessity of surgical reintervention on the MV once SAM is discovered by intraoperative transesophageal echocardiography. We sought to identify predictors of SAM in a large cohort of consecutive patients, assess the rate of early reintervention on the MV to address SAM, and follow the progression of SAM postdischarge. METHODS: Analysis of electronically stored echocardiographic exams of adults who underwent MV repair in a recent decade. RESULTS: Following MV repair, the incidence of SAM immediately after cardiopulmonary bypass was 13% (98 of 761 patients). Multivariable analysis revealed several preoperative risk factors of SAM development and progression, including a lower ratio of anterior to posterior leaflets heights, younger age, lower end-systolic left ventricular volume, presence of bileaflet prolapse, and male sex. SAM was managed conservatively in 91 patients (93%) and surgically in 7 patients (7%). In a majority of patients (70 of 98 patients [71%]) SAM resolved before hospital discharge. CONCLUSIONS: Transesophageal echocardiography findings associated with SAM were excessive height of posterior to anterior mitral leaflet, smaller left ventricular end-systolic volume, and bileaflet prolapse. Conservative management of SAM was usually successful, and persistent hemodynamically significant SAM was uncommon. Prophylactic modification of the surgical technique to avoid SAM seems unnecessary for all but those at highest risk for developing SAM.

What Factors Should Be Considered to Improve Outcome of Mechanical Mitral Valve Replacement in Children?

OBJECTIVE: To identify risk factors for pediatric mechanical mitral valve replacement (mMVR) to improve management in this challenging population. METHODS: From 1993 to 2019, 93 children underwent 119 mMVR operations (median age, 8.8 years [interquartile range [IQR]: 2.1-13.3], 54.6% females) at our institution. Twenty-six (21.8%) patients underwent mMVR at ≤2 years and 93 (78.2%) patients underwent mMVR at >2 years. Median follow-up duration was 7.6 years [IQR: 3.2-12.4]. RESULTS: Early mortality was 9.7%, but decreased with time and was 0% in the most recent era (13.9% from 1993 to 2000, 7.3% from 2001 to 2010, 0% from 2011 to 2019, P = .04). It was higher in patients ≤2 years compared to patients >2 years (26.9% vs 2.2%, P < .01). On multivariable analysis for mitral valve reoperation, valve size <23 mm was significant with a hazard ratio of 5.38 (4.87-19.47, P = .01);. Perioperative stroke occurred in 1% and permanent pacemaker was necessary in 12%. Freedom from mitral valve reoperation was higher in patients >2 years and those with a prosthesis ≥23 mm. Median time to reoperation was 7 years (IQR: 4.5-9.1) in patients >2 years and 3.5 years (IQR: 0.6-7.1) in patients ≤2 years (P = .0511), but was similar between prosthesis sizes (P = .6). During follow-up period (median 7.6 years [IQR: 3.2-12.4], stroke occurred in 10%, prosthetic valve thrombosis requiring reoperation in 4%, endocarditis in 3%, and bleeding in 1%. CONCLUSION: Early and late outcomes of mMVR in children are improved when performed at age >2 years and with prosthesis size ≥23 mm. These factors should be considered in the timing of mMVR.

Adult Intraoperative Echocardiography: A Comprehensive Review of Current Practice.

Intraoperative transesophageal echocardiography is a mature imaging modality and critical component of contemporary heart surgery, in which it plays a key role in surgical planning, determination of cardiac chamber filling and function early after cardiopulmonary bypass, and timely assessment of surgical interventions. Intraoperative transesophageal echocardiography affords the unique opportunity to correct suboptimal surgical results before leaving the operating room. Herein, the authors provide a comprehensive review of their institution's experience with intraoperative transesophageal echocardiography, emphasizing a practical assessment of commonly encountered noncongenital surgical heart lesions in adults, anticipation of potential surgical complications, and imaging approaches to facilitate timely surgical correction of unsatisfactory results.

Tricuspid valvectomy to facilitate repair of postinfarction ventricular septal defect.

Repair of postinfarction ventricular septal defect (VSD) located posteriorly can be a challenging procedure both in regard to operative mortality and recurrence of the defect. Avoidance of ventriculotomy by transatrial repair may decrease risks of bleeding and impairment of ventricular function secondary to suture placement; however, adequate exposure of the defect through the tricuspid valve is not always possible. We present a case of successful transatrial repair of posterior postinfarction VSD with concurrent tricuspid valvectomy and coronary artery grafting.

Prothrombin Complex Concentrates in Pediatric Cardiac Surgery: The Current State and the Future.

BACKGROUND: After decades of practice of pediatric cardiac surgery, postoperative bleeding due to the immaturity of hemostasis, hemodilution, and hypothermia remains a concern. Recently, a new approach for adult coagulopathy after bypass has emerged. Prothrombin complex concentrates (PCCs), designed to treat bleeding in hemophilia patients, are safely and efficiently used off label for hemorrhage after bypass. However, optimal dosing, indications and contraindications, and laboratory tests to assess the efficacy of PCC use in children have not yet been established. This literature review outlines the challenges of bypass-related coagulopathy, the pharmacology, and the experience in use of PCCs, with a focus on their potential in pediatric cardiac surgery. METHODS: After a thorough literature search of MEDLINE, Scopus, and Ovid databases using the term "prothrombin complex concentrate AND pediatric," 23 relevant articles were selected. RESULTS: The data supporting successful use of PCCs in acquired coagulopathy after cardiac surgery in adults have been increasing. Although small volume, low immunogenicity, efficiency, and speed in correcting coagulopathy are attractive qualities of PCCs for pediatric practice, current evidence is only anecdotal. The main concerns are unknown dosing regimens, the inability to closely monitor the effects of PCCs in real time, and a possibility of thrombotic complications, which can be particularly devastating in young congenital cardiac patients whose lives frequently depend upon the patency of artificial shunts. CONCLUSIONS: Extensive, high-quality research is warranted to fill in the gaps of knowledge regarding using PCCs in pediatric cardiac practice.

Association between bicuspid aortic valve morphotype and regional dilatation of the aortic root and trunk.

Thoracic aortic disease, including thoracic aortic aneurysm (TAA), is frequently seen in patients with bicuspid aortic valve (BAV). We hypothesized that BAV morphotype would be associated with aortic aneurysm phenotypes but that other patient variables would significantly modify this relationship. 829 patients between 18 and 90 years with BAV and available raw imaging of the aortic valve and the ascending aorta to its mid-portion prior to aortic valve and aortic surgery were examined. The sinuses of Valsalva and proximal ascending aorta were measured from 2-dimensional co-planar echocardiographic images. We observed strong associations between patient habitus and raw and normalized dimensions of the aortic root and ascending aorta. Patients with R-L morphotype presented at an older age with larger aortic root but similar ascending aortic dimensions. After accounting for patient morphometric characteristics and severity of aortic valve disease, patients with R-L valve morphotype were marginally more likely to have an aortic root aneurysm (86% vs. 78%; P = 0.043), defined as aortic root dimension Z score ≥3. We observed only small differences in aortic dimensions between BAV morphotypes, that are eclipsed by variation in patient habitus. We interpret these findings to mean that BAV patients will not likely benefit from therapies based on aortic valve morphotype. Rather, we propose that all BAV patients should undergo longitudinal follow-up, independent of valve morphotype. Guidelines for aortic surgery based upon dimensions alone may be improved by considering patient characteristics such as age, body size and other characteristics.