Christine Friedrich

Dr. Christine Friedrich

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Research Focus & Metrics

Academic Career Length

25Years (2002-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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18 June 2020 in Journal of Cardiothoracic Surgery
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Journal Article
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CFChristine Friedrich
Christine Friedrich
MSMohamed Ahmed Salem
Mohamed Ahmed Salem
TPThomas Puehler
Thomas Puehler
GHGrischa Hoffmann
Grischa Hoffmann
GLGeorg Lutter
Georg Lutter
AHAssad Haneya
Assad Haneya
Background: Although gender-related disparities in cardiovascular surgery have been investigated extensively in the past decades, knowledge about the impact of gender on outcomes after surgery for acute aortic dissection type A (AADA) is sparse. This study investigated the impact of gender on early morbidity and mortality and follow-up outcome in patients after surgery for AADA and to analyze gender-related risk factors for 30-day mortality. Methods: This retrospective study included 368 consecutive patients (male 65.8% vs. female 34.2%) undergoing surgery for AADA between 2001 and 2016 at our department. Survival was estimated by Kaplan-Meier curves. Risk factors for 30-day mortality were assessed by multivariable logistic regression and interaction analysis. Results: Women were older (70.7 years vs. 60.6 years; p < 0.001) and showed a higher logistic EuroSCORE I (31.0% vs. 19.7%, p < 0.001). In the male group, a higher portion of smokers (27.6% vs. 16.0%, p = 0.015) and intraoperatively, more complex procedures and longer cardiopulmonary bypass (CPB) (171 min vs. 149 min, p = 0.001) and cross-clamping times (94 min vs. 85 min, p = 0.018) occurred. 30-day mortality was 19.0% in the female and 16.5% in the male group (p = 0.545). Predictive for 30-day mortality in both genders was intraoperative blood transfusion, while in the female group chronic obstructive pulmonary disease (COPD), peripheral arterial disease and preoperative intubation were predictive. Preoperative cardiopulmonary resuscitation and duration of CPB time were predictors only in males. Averaged follow-up time was 5.2 years and survival did not differ between genders, even if it was stratified by age over 70 years. Conclusions: This analysis demonstrated a similar and satisfactory survival in both genders after surgical treatment of AADA. Women and men differed significantly in age, unadjusted and adjusted risk factors and complexity of surgical treatment, but gender itself was no risk factor for mortality. These results suggest that the decision-making for surgical treatment should not depend on gender, but that accounting for sex-specific risk factors rather than common risk factors may help to improve the outcome in both genders.

Verified
Journal Article
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TPThomas Puehler
Thomas Puehler
CFChristine Friedrich
Christine Friedrich
GLGeorg Lutter
Georg Lutter
MKMaike Kornhuber
Maike Kornhuber
MSMohamed Salem
Mohamed Salem
AHAssad Haneya
Assad Haneya
The study was approved by the institutional review board (IRB) at the University Medical Center Campus Kiel, Kiel, Germany (reference number: AZ D 559/18) and registered at the German Clinical Trials Register (reference number: DRKS00022222). Objective. Unilateral pulmonary edema (UPE) is a complication after minimally invasive mitral valve surgery (MIMVS). We analyzed the impact of this complication on the short- and long-term outcome over a 10-year period. Methods. We retrospectively observed 393 MIMVS patients between 01/2009 and 12/2019. The primary endpoint was a radiographically and clinically defined UPE within the first postoperative 24 h, secondary endpoints were 30-day and long-term mortality and the percentage of patients requiring ECLS. Risk factors for UPE incidence were evaluated by logistic regression, and risk factors for mortality in the follow-up period were assessed by Cox regression. Results. Median EuroSCORE II reached 0.98% in the complete MIMVS group. Combined 30-day and in-hospital mortality after MIMVS was 2.0% with a 95, 93 and 77% survival rate after 1, 3 and 10 years. Seventy-two (18.3%) of 393 patients developed a UPE 24 h after surgery. Six patients (8.3%) with UPE required an extracorporeal life-support system. Logistic regression analysis identified a higher creatinine level, a worse LV function, pulmonary hypertension, intraoperative transfusion and a longer aortic clamp time as predictors for UPE. Combined in hospital mortality and 30-day mortality was slightly but not significantly higher in the UPE group (4.2 vs. 1.6%; p = 0.17). Predictors for mortality during follow-up were age ≥ 70 years, impaired RVF, COPD, drainage loss ≥ 800 mL and length of ventilation ≥ 48 h. During a median follow-up of 4.6 years, comparable survival between UPE and non-UPE patients was seen in our analysis after 5 years (89 vs. 88%; p = 0.98). Conclusions. In-hospital outcome with UPE after MIMVS was not significantly worse compared to non-UPE patients, and no differences were observed in the long-term follow-up. However, prolonged aortic clamp time, worse renal and left ventricular function, pulmonary hypertension and transfusion are associated with UPE.

26 April 2021 in Journal of Clinical Medicine
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Journal Article
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MSMohamed Salem
Mohamed Salem
CFChristine Friedrich
Christine Friedrich
Mohammed SaadMohammed Saad
Mohammed Saad
DFDerk Frank
Derk Frank
MSMostafa Salem
Mostafa Salem
AHAssad Haneya
Assad Haneya
Background: Active infective endocarditis (IE) is a serious disease associated with high mortality. The current study represents our experience over 18 years with surgical treatment for active infective native and prosthetic valve endocarditis (INVE, IPVE). Method: Analysis of 413 patients (171 with IPVE vs. 242 with INVE) who underwent cardiac surgery due to IE between 2002 and 2020. Results: Patients with IPVE were significantly older (64.9 ± 13.2 years vs. 58.3 ± 15.5 years; p < 0.001) with higher EuroSCORE II (21.2 (12.7; 41.8) vs. 6.9 (3.0; 17.0); p < 0.001)) and coronary heart disease (50.6% vs. 38.0%; p < 0.011). Preoperative embolization was significantly higher within INVE (35.5% vs. 16.4%; p < 0.001) with high incidence of cerebral embolization (18.6% vs. 7.6%; p = 0.001) and underwent emergency curative surgery than the IPVE group (19.6% vs. 10.6%; p < 0.001). However, patients with IPVE were significantly represented with intracardiac abscess (44.4% vs.15.7%; p < 0.001). Intraoperatively, the duration of surgery was expectedly significantly higher in the IPVE group (356 min vs. 244 min.; p = 0.001) as well as transfusion of blood (4 units (0–27) vs. 2 units (0–14); p < 0.001). Post-operatively, the incidence of bleeding was markedly higher within the IPVE group (700 mL (438; 1163) vs. 500 mL (250; 1075); p = 0.005). IPVE required significantly more permanent pacemakers (17.6% vs. 7.5%: p = 0.002). The 30-day mortality was higher in the IPVE group (24.6% vs. 13.2%; p < 0.003). Conclusion: Patients with INVE suffered from a higher incidence of cerebral embolization and neurological deficits than patients with IPVE. Surgical treatment in INVE is performed mostly as an emergency indication. However, patients with IPVE were represented commonly with intracardiac abscess, and had a higher indication of pacemaker implantation. The short- and long-term mortality rate among those patients was still high.

28 March 2022 in Journal of Clinical Medicine
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CFChristine Friedrich
Christine Friedrich
MSMohamed Salem
Mohamed Salem
TPThomas Puehler
Thomas Puehler
BPBernd Panholzer
Bernd Panholzer
LHLea Herbers
Lea Herbers
AHAssad Haneya
Assad Haneya
(1) Background: Surgery for infective endocarditis (IE) is associated with considerable mortality and it is controversial whether the female gender is predictive for a worse outcome. This large single-center study investigated the impact of sex on outcomes after surgery for IE. (2) Methods: 413 patients (25.4% female) were included into this retrospective observational study. Univariate and multivariable analyses identified sex-specific risk factors for 30 day and late mortality. Survival was estimated by the Kaplan-Meier-method. (3) Results: Women presented more often with mitral valve infection (p = 0.039). Men presented more frequently with previous endocarditis (p = 0.045), coronary heart disease (p = 0.033), and aortic valve infection (p = 0.005). Blood transfusion occurred more frequently intraoperatively in women (p < 0.001), but postoperatively in men (p = 0.015) and men had a longer postoperative stay (p = 0.046). Women showed a higher 30 day mortality than men (p = 0.007) and female gender was predictive for 30 day mortality (OR 2.090). Late survival showed no sex-specific difference (p = 0.853), and the female gender was not an independent predictor for late mortality (p = 0.718). Risk factors for early and late mortality showed distinct sex-specific differences such as increased preoperative CRP level in women and culture-negative IE in men.

19 June 2020 in The Thoracic and Cardiovascular Surgeon
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Journal Article
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MSMohamed Salem
Mohamed Salem
CFChristine Friedrich
Christine Friedrich
ATAlexander Thiem
Alexander Thiem
KHKatharina Huenges
Katharina Huenges
TPThomas Puehler
Thomas Puehler
AHAssad Haneya
Assad Haneya
Introduction Acute aortic dissection Type A (AADA) is still associated with a high mortality rate and frequent postoperative complications. This study was designed to evaluate the risk factors for mortality in AADA patients. Patients and Methods This retrospective analysis included 344 consecutive patients who underwent surgery for AADA in moderate hypothermic circulatory arrest (20–24°C nasopharyngeal) between 2001 and 2016. Results The 30-day mortality rate was 18%. Nonsurvivors were significantly older (65.7 ± 12.0 years vs. 62.0 ± 12.5 years; p = 0.034) with significantly higher Euro-score II [15.4% (6.6; 23.0) vs. 4.63% (2.78; 9.88); p < 0.001)]. Intraoperatively, survivors had statistically shorter cardiopulmonary bypass times [163 (134; 206) vs. 198 min (150; 245); p = 0.001]. However, the hypothermic circulatory arrest time was similar between both groups. Postoperatively, the incidence of acute kidney injury (AKI) (55.9 vs. 15.2%; p < 0.001), stroke (27.9 vs. 12.1%; p = 0.002) and sepsis (18.0 vs. 2.1%; p < 0.001) were significantly higher among nonsurvivors. The multi-variable logistic regression confirmed that older age, previous cardiac surgery, preoperative cardiopulmonary resuscitation (CPR), blood transfusion and postoperative acute kidney injury (AKI) were independent risk factors for mortality. Conclusion Our analysis suggested that the reason for mortality was multifactorial, especially age, previous cardiac surgery, CPR, transfusion, as well as postoperative AKI were considered risk factors for mortality.

1 July 2002 in Polar Biology
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WIWerner I.
Werner I.
AHAuel H.
Auel H.
CFChristine Friedrich
Christine Friedrich