Prosthetic Valve Malfunction; Etiologies, Treatment Strategies and Treatment Outcomes: A Descriptive-analytic Study

    Authors

    Abstract

    Valvular heart diseases are common worldwide and are associated with a high rate of mortality and morbidity. Surgical valve replacement is the most important treatment for valvular diseases. One of the most important complications of this treatment is prosthetic valve malfunction which requires rapid diagnosis and treatment. In this study, we examined the etiologies, treatment strategies, and treatment outcomes in a series of patients with prosthetic valve malfunction. In this cross-sectional, analytic-descriptive study, 63 cases in 52 patients with prosthetic valve malfunction were included. Their coagulation status, demographic, and clinical information was collected in a questionnaire. Patients treatment and their outcomes or rehospitalization rate was recorded as well. Data were analyzed using SPSS 20 software. In our study population, average age was 49.98±14.31, and 53.9% of patients were women. Among 63 cases, 57 of them had mechanical valve malfunction and 6 of them had biological valve malfunction. All cases of mechanical valve malfunction were caused by thrombosis. Surgery was the most common treatment strategy and was associated with excellent outcomes compared with other strategies (p=0.002). In this study, we observed acceptable outcomes for thrombolytic therapy. Thrombosis was the most frequent cause of prosthetic valve malfunction in this study, which seems to be due to inadequate anticoagulant therapy. It can be concluded that educating and following patients for their accurate coagulation status is necessary for decreasing prosthetic valve malfunction. We also found surgical treatment to be significantly better than other treatments.

    Keywords

    valve prosthesis, surgical valve, thrombosis, thrombolytic therapy, heart valve diseases

    DOI

    https://doi.org/10.15836/ccar2020.255

    Full Text

    ## Introduction Valvular heart diseases involve more than 100 000 000 people around the world with a prevalence of 2.5% in the USA and is associated with high rate of mortality and morbidity. Surgical valve replacement is the most important treatment strategy for valvular diseases, resulting in excellent long term out comes ( 1 ). Surgical valve replacement can lead to short-term complications causing disability or death. Prosthetic valve malfunction is one of the most important complications which can be dangerous and lethal in patients and requires rapid diagnosis and treatment ( 2 ). Prosthetic valve malfunctions can be categorized as obstructive or insufficiency malfunctions ( 3 ). Among obstructive malfunctions, prosthetic valve thrombosis requires rapid diagnosis and treatment and is usually associated with acute presentations such as dyspnea, acute pulmonary edema, chest pain, stroke, or peripheral emboli ( 4 ). In transthoracic echocardiography (TTE) it can be associated with elevated pressure gradient and no or impaired leaflet movement ( 5 ). First-line treatment options include repeated surgery, thrombolytic therapy, or intensive anticoagulant therapy which depends on location and size of the thrombosis, patients functional class of dyspnea, surgical risk, or physicians experience, etc. ( 6 ). Given the dangerous complications of impaired prosthetic valve function and efficacy and outcomes of the abovementioned treatments, we decided to investigate a series of patients with prosthetic valve malfunction for patient condition, the cause of malfunction, applied treatment strategies, and outcomes of treatment in the Afshar Heart Center during a 3-year period. ## Patients and Methods We decided to perform a cross-sectional, descriptive-analytic study on all patients diagnosed with prosthetic valve malfunction via TTE or fluoroscopy referred to the Afshar Heart Center betwen 2015 and 2017. All patients signed an informed consent form allowing their medical and demographic information to be used for research purposes. We designed and carried out this study based on the latest Helsinki declaration. We included all patients with prosthetic valve malfunction between 2015 and 2017 referred to the Afshar Heart Center, Yazd, Iran; patients with prosthetic valve malfunction due to endocarditis, technical errors such as mismatch, and pressure recovery were excluded. Finally, 52 patients (63 cases) were enrolled and their coagulation status and demographic, clinical, and para-clinical information was collected. Data including age, gender, time passed after surgical valve replacement, previous history of prosthetic valve malfunction, history of stroke, clinical manifestations, patients dyspnea functional class, cardiac rhythm, international normalized ratio (INR), left ventricular ejection fraction (LVEF), abnormal echocardiography of fluoroscopy findings, performed treatments, and treatment outcomes were collected using a questionnaire and data were analyzed using SPSS 20 software. Descriptive statistics are reported as mean±SD, percentage, and frequency. In this study, all analyzed variables were nominal and categorical and thus the Chi-square test was used in all cases. Descriptive results are presented in the form of descriptive and frequency tables, while analytic results are reported as P-values; in all cases, a 2-tailed P-value<0.05 was considered to be statistically significant. In this paper we only analyzed and report main findings focused on treatment strategies and their outcomes. Other detailed information is always available and will be made available to interested researchers or readers contacting the corresponding author. ## Results This study included 63 cases in 52 patients with prosthetic valve malfunction admitted to the Afshar Heart Center during 2015 and 2017. Two patients were excluded because of mismatch. The average age was 49.98±14.31 in our population. Detailed descriptive statistical information of our study population is summed up in Table 1 . Of the total 63 cases, 57 (90.4%) had mechanical valve malfunction and 6 (9.6%) had biological valve malfunction. Average time since surgical valve replacement was 5.65±4.89 years, and the peak for mechanical valve malfunction was in the first 3 years after surgery as seen in Figure 1 . Average time after surgical valve replacement before prosthetic valve malfunction, 5.65±4.89. The malfunction etiology responsible for all cases with mechanical valve was thrombosis, which associated with pannus formation in 12 cases. Among cases with mechanical valve thrombosis, 42 patients (73.6%) had valvular obstruction and 15 cases (26.4%) were non-obstructive. Among patients with biological valve malfunction, 4 cases with degenerative changes were observed, which were associated with thrombosis in 2 cases. In 42 cases with obstructive thrombosis, 14 (33.3%) cases received thrombolytic therapy and 28 (66.7%) of them were selected for surgical treatment. Among selected patients, 21 of them eventually underwent surgery, of which 20 patients had complete recovery and 1 mortality was recorded. Among 14 cases who received thrombolytic therapy, 10 (71.4%) had complete recovery, 2 cases (14.3%) had partial recovery, and 2 patients (14.3%) developed intracranial hemorrhage (ICH) due to treatment. No embolic cerebrovascular accidents (CVA) or deaths were recorded following thrombolytic therapy. In this study population, 21 patients underwent surgery, 14 patients received thrombolytic treatment, and 28 patients received intensive anticoagulant therapy. Among cases who received anticoagulant therapy, 17 cases had non-obstructive thrombosis and 11 cases were selected for surgery but did not undergo surgery for various reasons such as high risk of surgery, comorbidity, etc. The frequency of treatment strategies is shown in Table 2 . When comparing response to treatment and treatment outcomes, surgical treatment was significantly better than other treatment strategies. Based on performed treatments, 44 cases had complete recovery, 16 cases had partial recovery or were suggested for another elective surgery, and our treatment failed in 3 patients due to treatment complications. In one of the failed treatments, the patient developed respiratory distress following thrombolytic therapy and underwent surgical treatment during the same hospitalization, while patients in the other two failed cases developed ICH because of thrombolytic therapy, for which 1 underwent surgery and 1 received conservative treatment. Treatment outcomes are summed up in Table 3 . Based on the Chi-square test, there was a statistically significant difference (p=0.002) in treatment outcomes based on different treatment strategies. In the present study, 11 cases of rehospitalization were recorded in 9 patients, with 1 patient who had 3 hospitalization episodes because of valvular malfunction. In 3 cases, the involved valve was different from the previous hospitalization. Average time to rehospitalization was 1.82±3.82 months after previous hospitalization as seen in Figure 2 . Average time before rehospitalization, 1.82±3.82. The frequency of rehospitalization cases is presented in Table 4 below. Based on the Chi-square test, there was no statistically significant difference in number of rehospitalizations based on received treatment (p=0.825). ## Discussion During this study, we included and examined 63 cases of prosthetic valve malfunction in 52 patients over a period of 3 years. In other similar studies, this number was significantly lower despite a longer study period ( 7 , 8 ), for example in a study performed by Dürrleman et al. that examined only 39 cases of prosthetic valve thrombosis over a period of 20 years ( 9 ) and Wei-Guo Ma et al. who only reported on 48 patients with prosthetic valve malfunction over a period of 15 years ( 10 ). Different reasons can be suggested for such a difference including: 1) our study center is a referral center that gathers patients from other centers; 2) some studies excluded patients with biological valves; 3) higher rate of non-obstructive thrombosis in our study compared to similar studies; 4) less compliance of our study population in using prescribed anticoagulant agents; 5) lack of a good registry and follow-up system for patients. In our study, the average age of patients was 49.98±14.31, and 53.9% of our cases were women. In other similar studies, women were also more numerous than men (but with a bigger difference) and the average age was not very different, being both lower and higher in some studies ( 8 , 11 , 12 ). The average time since surgical valve replacement before valvular malfunction in our study was 5.65±4.89 years with a peak at 3 years. This variable was different in different similar studies. For example, Fidel Manuel Cáceres-Lóriga reported this average time to be 6.8 years ( 7 ). This difference can be due to environmental and genetic differences in the studied populations. We observed thrombosis in 59 cases (93.6%), which was obstructive in 70.2% of cases. In our study population, 18.97% of thrombosis cases were associated with pannus formation, whereas in 2 cases (3.7%) thrombosis was associated with degenerative changes in biological valves. In other similar studies, thrombosis was also reported to be the most common etiology for prosthetic valve malfunction and other etiologies such as pannus formation were mostly observed together with underlying thrombosis ( 13 , 14 ). These findings are confirmed by our study, and the principal reason seems to be inadequate antithrombotic therapy in patients after surgical valve replacement. For example, in a study by Ahmad Separham et al., thrombosis was observed in all patients and reported as obstructive in 88.3% of cases, and was associated with pannus formation in 26.7% of cases ( 15 ). Among patients with obstructive thrombosis in our study, 28 patients (66.7%) were selected for repeated surgery, of which 21 underwent surgery whereas the other 7 patients received intensive anticoagulant therapy. Among 21 surgical cases, 20 achieved complete recovery and 1 mortality was recorded due to acute respiratory distress. In similar studies, surgery was selected more than other treatment strategies, which is similar to our findings (60% of patients underwent surgery) ( 16 , 17 ). In most previous studies ( 18 , 19 ), success rate of surgery was higher than the success rate of thrombolytic treatment, although we also achieved an acceptable success rate using thrombolytic therapy, similar to the study by Fidel Manuel Cáceres-Lóriga’s ( 20 ). This can lead to the conclusion that thrombolytic treatment can be an important treatment strategy and a good alternative for surgery in prosthetic valve malfunction with lower risk of emboli. ## Conclusion In our study, as in other similar studies, we found thrombosis to be the most common etiology for prosthetic valve malfunction, which is mainly due to inadequate anticoagulant therapy. We can conclude that to decrease incidence of prosthetic valve malfunction, educating patients and encouraging them to control and record their coagulation status can remove a considerable burden of treatment of prosthetic valve malfunction.

    Cardiologia Croatica
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    Prosthetic Valve Malfunction; Etiologies, Treatment Strategies and Treatment Outcomes: A Descriptive-analytic Study

    Original Scientific Paper
    Issue9-10
    Published
    Pages255-261
    PDF via DOIhttps://doi.org/10.15836/ccar2020.255
    valve prosthesis
    surgical valve
    thrombosis
    thrombolytic therapy
    heart valve diseases

    Authors

    Hasan HaghaninejadORCIDShahid Sadoughi University of Medical Sciences, Yazd, Iran
    Farkhondeh KhaleghiORCIDShahid Sadoughi University of Medical Sciences, Yazd, Iran
    Aryan Naghedi*ORCIDShahid Sadoughi University of Medical Sciences, Yazd, Iran

    Abstract

    Valvular heart diseases are common worldwide and are associated with a high rate of mortality and morbidity. Surgical valve replacement is the most important treatment for valvular diseases. One of the most important complications of this treatment is prosthetic valve malfunction which requires rapid diagnosis and treatment. In this study, we examined the etiologies, treatment strategies, and treatment outcomes in a series of patients with prosthetic valve malfunction. In this cross-sectional, analytic-descriptive study, 63 cases in 52 patients with prosthetic valve malfunction were included. Their coagulation status, demographic, and clinical information was collected in a questionnaire. Patients treatment and their outcomes or rehospitalization rate was recorded as well. Data were analyzed using SPSS 20 software. In our study population, average age was 49.98±14.31, and 53.9% of patients were women. Among 63 cases, 57 of them had mechanical valve malfunction and 6 of them had biological valve malfunction. All cases of mechanical valve malfunction were caused by thrombosis. Surgery was the most common treatment strategy and was associated with excellent outcomes compared with other strategies (p=0.002). In this study, we observed acceptable outcomes for thrombolytic therapy. Thrombosis was the most frequent cause of prosthetic valve malfunction in this study, which seems to be due to inadequate anticoagulant therapy. It can be concluded that educating and following patients for their accurate coagulation status is necessary for decreasing prosthetic valve malfunction. We also found surgical treatment to be significantly better than other treatments.

    Full Text

    ## Introduction Valvular heart diseases involve more than 100 000 000 people around the world with a prevalence of 2.5% in the USA and is associated with high rate of mortality and morbidity. Surgical valve replacement is the most important treatment strategy for valvular diseases, resulting in excellent long term out comes ( 1 ). Surgical valve replacement can lead to short-term complications causing disability or death. Prosthetic valve malfunction is one of the most important complications which can be dangerous and lethal in patients and requires rapid diagnosis and treatment ( 2 ). Prosthetic valve malfunctions can be categorized as obstructive or insufficiency malfunctions ( 3 ). Among obstructive malfunctions, prosthetic valve thrombosis requires rapid diagnosis and treatment and is usually associated with acute presentations such as dyspnea, acute pulmonary edema, chest pain, stroke, or peripheral emboli ( 4 ). In transthoracic echocardiography (TTE) it can be associated with elevated pressure gradient and no or impaired leaflet movement ( 5 ). First-line treatment options include repeated surgery, thrombolytic therapy, or intensive anticoagulant therapy which depends on location and size of the thrombosis, patients functional class of dyspnea, surgical risk, or physicians experience, etc. ( 6 ). Given the dangerous complications of impaired prosthetic valve function and efficacy and outcomes of the abovementioned treatments, we decided to investigate a series of patients with prosthetic valve malfunction for patient condition, the cause of malfunction, applied treatment strategies, and outcomes of treatment in the Afshar Heart Center during a 3-year period. ## Patients and Methods We decided to perform a cross-sectional, descriptive-analytic study on all patients diagnosed with prosthetic valve malfunction via TTE or fluoroscopy referred to the Afshar Heart Center betwen 2015 and 2017. All patients signed an informed consent form allowing their medical and demographic information to be used for research purposes. We designed and carried out this study based on the latest Helsinki declaration. We included all patients with prosthetic valve malfunction between 2015 and 2017 referred to the Afshar Heart Center, Yazd, Iran; patients with prosthetic valve malfunction due to endocarditis, technical errors such as mismatch, and pressure recovery were excluded. Finally, 52 patients (63 cases) were enrolled and their coagulation status and demographic, clinical, and para-clinical information was collected. Data including age, gender, time passed after surgical valve replacement, previous history of prosthetic valve malfunction, history of stroke, clinical manifestations, patients dyspnea functional class, cardiac rhythm, international normalized ratio (INR), left ventricular ejection fraction (LVEF), abnormal echocardiography of fluoroscopy findings, performed treatments, and treatment outcomes were collected using a questionnaire and data were analyzed using SPSS 20 software. Descriptive statistics are reported as mean±SD, percentage, and frequency. In this study, all analyzed variables were nominal and categorical and thus the Chi-square test was used in all cases. Descriptive results are presented in the form of descriptive and frequency tables, while analytic results are reported as P-values; in all cases, a 2-tailed P-value<0.05 was considered to be statistically significant. In this paper we only analyzed and report main findings focused on treatment strategies and their outcomes. Other detailed information is always available and will be made available to interested researchers or readers contacting the corresponding author. ## Results This study included 63 cases in 52 patients with prosthetic valve malfunction admitted to the Afshar Heart Center during 2015 and 2017. Two patients were excluded because of mismatch. The average age was 49.98±14.31 in our population. Detailed descriptive statistical information of our study population is summed up in Table 1 . Of the total 63 cases, 57 (90.4%) had mechanical valve malfunction and 6 (9.6%) had biological valve malfunction. Average time since surgical valve replacement was 5.65±4.89 years, and the peak for mechanical valve malfunction was in the first 3 years after surgery as seen in Figure 1 . Average time after surgical valve replacement before prosthetic valve malfunction, 5.65±4.89. The malfunction etiology responsible for all cases with mechanical valve was thrombosis, which associated with pannus formation in 12 cases. Among cases with mechanical valve thrombosis, 42 patients (73.6%) had valvular obstruction and 15 cases (26.4%) were non-obstructive. Among patients with biological valve malfunction, 4 cases with degenerative changes were observed, which were associated with thrombosis in 2 cases. In 42 cases with obstructive thrombosis, 14 (33.3%) cases received thrombolytic therapy and 28 (66.7%) of them were selected for surgical treatment. Among selected patients, 21 of them eventually underwent surgery, of which 20 patients had complete recovery and 1 mortality was recorded. Among 14 cases who received thrombolytic therapy, 10 (71.4%) had complete recovery, 2 cases (14.3%) had partial recovery, and 2 patients (14.3%) developed intracranial hemorrhage (ICH) due to treatment. No embolic cerebrovascular accidents (CVA) or deaths were recorded following thrombolytic therapy. In this study population, 21 patients underwent surgery, 14 patients received thrombolytic treatment, and 28 patients received intensive anticoagulant therapy. Among cases who received anticoagulant therapy, 17 cases had non-obstructive thrombosis and 11 cases were selected for surgery but did not undergo surgery for various reasons such as high risk of surgery, comorbidity, etc. The frequency of treatment strategies is shown in Table 2 . When comparing response to treatment and treatment outcomes, surgical treatment was significantly better than other treatment strategies. Based on performed treatments, 44 cases had complete recovery, 16 cases had partial recovery or were suggested for another elective surgery, and our treatment failed in 3 patients due to treatment complications. In one of the failed treatments, the patient developed respiratory distress following thrombolytic therapy and underwent surgical treatment during the same hospitalization, while patients in the other two failed cases developed ICH because of thrombolytic therapy, for which 1 underwent surgery and 1 received conservative treatment. Treatment outcomes are summed up in Table 3 . Based on the Chi-square test, there was a statistically significant difference (p=0.002) in treatment outcomes based on different treatment strategies. In the present study, 11 cases of rehospitalization were recorded in 9 patients, with 1 patient who had 3 hospitalization episodes because of valvular malfunction. In 3 cases, the involved valve was different from the previous hospitalization. Average time to rehospitalization was 1.82±3.82 months after previous hospitalization as seen in Figure 2 . Average time before rehospitalization, 1.82±3.82. The frequency of rehospitalization cases is presented in Table 4 below. Based on the Chi-square test, there was no statistically significant difference in number of rehospitalizations based on received treatment (p=0.825). ## Discussion During this study, we included and examined 63 cases of prosthetic valve malfunction in 52 patients over a period of 3 years. In other similar studies, this number was significantly lower despite a longer study period ( 7 , 8 ), for example in a study performed by Dürrleman et al. that examined only 39 cases of prosthetic valve thrombosis over a period of 20 years ( 9 ) and Wei-Guo Ma et al. who only reported on 48 patients with prosthetic valve malfunction over a period of 15 years ( 10 ). Different reasons can be suggested for such a difference including: 1) our study center is a referral center that gathers patients from other centers; 2) some studies excluded patients with biological valves; 3) higher rate of non-obstructive thrombosis in our study compared to similar studies; 4) less compliance of our study population in using prescribed anticoagulant agents; 5) lack of a good registry and follow-up system for patients. In our study, the average age of patients was 49.98±14.31, and 53.9% of our cases were women. In other similar studies, women were also more numerous than men (but with a bigger difference) and the average age was not very different, being both lower and higher in some studies ( 8 , 11 , 12 ). The average time since surgical valve replacement before valvular malfunction in our study was 5.65±4.89 years with a peak at 3 years. This variable was different in different similar studies. For example, Fidel Manuel Cáceres-Lóriga reported this average time to be 6.8 years ( 7 ). This difference can be due to environmental and genetic differences in the studied populations. We observed thrombosis in 59 cases (93.6%), which was obstructive in 70.2% of cases. In our study population, 18.97% of thrombosis cases were associated with pannus formation, whereas in 2 cases (3.7%) thrombosis was associated with degenerative changes in biological valves. In other similar studies, thrombosis was also reported to be the most common etiology for prosthetic valve malfunction and other etiologies such as pannus formation were mostly observed together with underlying thrombosis ( 13 , 14 ). These findings are confirmed by our study, and the principal reason seems to be inadequate antithrombotic therapy in patients after surgical valve replacement. For example, in a study by Ahmad Separham et al., thrombosis was observed in all patients and reported as obstructive in 88.3% of cases, and was associated with pannus formation in 26.7% of cases ( 15 ). Among patients with obstructive thrombosis in our study, 28 patients (66.7%) were selected for repeated surgery, of which 21 underwent surgery whereas the other 7 patients received intensive anticoagulant therapy. Among 21 surgical cases, 20 achieved complete recovery and 1 mortality was recorded due to acute respiratory distress. In similar studies, surgery was selected more than other treatment strategies, which is similar to our findings (60% of patients underwent surgery) ( 16 , 17 ). In most previous studies ( 18 , 19 ), success rate of surgery was higher than the success rate of thrombolytic treatment, although we also achieved an acceptable success rate using thrombolytic therapy, similar to the study by Fidel Manuel Cáceres-Lóriga’s ( 20 ). This can lead to the conclusion that thrombolytic treatment can be an important treatment strategy and a good alternative for surgery in prosthetic valve malfunction with lower risk of emboli. ## Conclusion In our study, as in other similar studies, we found thrombosis to be the most common etiology for prosthetic valve malfunction, which is mainly due to inadequate anticoagulant therapy. We can conclude that to decrease incidence of prosthetic valve malfunction, educating patients and encouraging them to control and record their coagulation status can remove a considerable burden of treatment of prosthetic valve malfunction.